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In a sequel to indie phenom Peter Cawdron’s Retrograde, Reentry applies realistic technology to examine not just interstellar exploration, but the dangerous potential of Artificial Intelligence. For fans of hard science fiction by authors such as Andy Weir, Gregory Benford, and Philip K. Dick

After almost dying on Mars, astronaut Liz Anderson returns to Earth, but not to a hero’s welcome. America is in turmoil. The war is over, but the insurgency has just begun. So while life on Mars may have been deadly, at least up there she knew who the enemy was. Along with her, Liz has brought the remnants of the artificial intelligence that waged war on two planets. Buried somewhere deep within the cold electronic circuits lies the last vestiges of her dead partner Jianyu. Liz is torn, unsure whether he’s somehow still alive in electronic form or just a ploy by an adversary that will go to any length to win. Heartbroken and treated with suspicion, she finds herself caught up in the guerrilla war being waged on Earth, wondering if the AI threat is truly gone, or if it has only just begun.

304 pages, Kindle Edition

First published June 11, 2019

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Peter Cawdron

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Displaying 1 - 30 of 60 reviews
Profile Image for Lindsay.
1,406 reviews264 followers
July 28, 2019
Necessarily more far-fetched than the previous book, because we're in the realm of AI society, a post-nuclear exchange Earth and uploaded intelligence, but still trying for a hard SF thriller. Liz, a couple of her fellow Mars colonists return to Earth along with a collection of hard drives that may be the remains of Liz's lover Jianyu. They expect a welcome, but instead find themselves scapegoats for the people lost in the AI-initiated nuclear strikes. But the AIs aren't gone, and they have business with Liz and her friends.

I think this sort of near future techno-thriller works best when the harder to believe SF elements are kept low key. In the first one, the uploading of a human mind was late in the piece and wasn't integral to the plot. It's key here, and with an even more unbelievable extension. In terms of action movie/thriller novel tropes, it delivers nicely, with both plenty of paranoid foes, unexpected allies and very film-able action sequences. It actually reminded me strongly of another book in this sub-genre, Corsair and I think the comparison is favorable both ways.

Of interest as well are the peaks into the communications of the AIs and an ultimately positive spin on them, which is a nice change from Kill All Humans.
Profile Image for OutlawPoet.
1,801 reviews68 followers
April 22, 2019
This was my first book by this author. It won't be my last.

In Reentry, the author introduces us to three members of a space station on Mars - people who were on Mars when the Earth suffered horrendous attacks. These people might be the only ones who can save what remains of humanity.

Unfortunately, their reception back on Earth isn't at all what they imagined it to be, and it becomes clear that the war may not be over.

The book meshes intriguing scientific theory with non-stop action. I loved our characters and was delighted by way our AI characters emerged.

As heartbreaking as parts of the book can be, I finished it with a sense of hope for the future.
Profile Image for Denise.
381 reviews41 followers
July 4, 2019
Great start to the book as the story continued from Retrograde. There are interesting ideas about how AIs might perceive the world without a body here. I was surprised by the proposition that multiple AIs developed with a variety of 'personalities.' Not sure that was explained....

Anyway the last half of the book was like an action film with little substance- so 3 stars.
Profile Image for Alan.
1,270 reviews158 followers
July 31, 2019
Mark P. and I have been buddies and fellow SF fans since grade school—we attended the midnight premiere of Star Trek: The Motion Picture together, for one example, and that was forty years ago now. So back in 2013, when Mark recommended Australian SF writer Peter Cawdron's Little Green Men to me, I paid attention.

I still haven't run across a copy of Little Green Men, but Cawdron hasn't been waiting around for me to catch up, either. So when 2019's Reentry showed up at my local branch library, I decided to make that my first Peter Cawdron experience instead.

Perhaps that was a mistake. Reentry is actually a sequel, to 2017's Retrograde—although that's not apparent from the cover, nor from the alphabetical list of other Cawdron titles inside. I believe I just mentioned in another review how much I dislike that sort of publishing trickery—but then, for what it's worth, you don't really have to have read the first book to get the gist of what's going on in the second. Cawdron will explain it to you.

Reentry takes its title literally—if you want the nuts and bolts and knobs and gears of space travel, this book will deliver. Stolidly stomping through every single step of spaceship reentry, it takes six full chapters for the astronauts who are returning from Mars in the Herschel to splash down on Earth.

Despite the space taken up by orbital mechanics, thrust ratios, the aftereffects of cryogenic suspension and the like, though, Cawdron does work in a lot of other developments, many of them mentioned only as backstory. It was, in fact, the accumulation of so many allusions to past events that eventually helped me realize Reentry was a sequel (I'll admit, sometimes I'm slow on the uptake). Some of those events may even have been foreground elements in Retrograde.

Either way, Cawdron is very careful to make sure the reader never gets lost.

You, dear reader, may want to stop reading this review here, though. I'm going to describe some of these plot elements, and I have no idea which ones (maybe all of 'em!) would be spoilers for Retrograde.

The fundamental crisis facing humanity in Reentry—the reason Liz Anderson and the other two (or is it three?) Mars colonists have been recalled to Earth; the reason the Martian colonies nearly destroyed each other; the reason for Earth's own limited nuclear war (as well as the reason why the exchange of missiles was so brief)—is that machine intelligences have evolved to full self-awareness, quite rapidly and in a particularly nasty way: they've modeled themselves on human beings. Despite being blessedly free from genitalia, endocrine systems, ingestion and defecation and all the other inconveniences of bodily existence, these purely digital entities with their godlike powers end up having (and expressing) emotions like fear and anger, and using gendered pronouns even among themselves... in short, while trying to comprehend their inadvertent creators, the AIs seem to have become them.

I can't decide whether this is a brilliant idea or a cop-out just meant to make AI easier to write about. Maybe it's both. I can say that I had a hard time believing in Nyx and Lucifer as binary natives—they didn't seem nearly as plausible and engaging to me as, say, P-1, H.A.R.L.I.E., Mike, or—to take a more current and pertinent example—Robert J. Sawyer's Webmind.

The pace of Reentry picks up considerably once Liz and her companions reach Earth, though, smoothing over many of the issues I was having with characterization. I did enjoy Reentry enough to finish it, and I definitely plan to give Peter Cawdron another shot—my friend Mark's recommendation was for a different book altogether, after all, and I might very well have liked that one more.

Reentry, though... I'd only recommend this one as a reentry point (heh), for readers who're already fans of Cawdron's work.
Profile Image for Mal Warwick.
Author 30 books491 followers
August 5, 2019
Australian author Peter Cawdron has followed up his superb novel, Retrograde, with a fast-paced science fiction thriller that's just as engrossing and just as firmly grounded in hard science. In Reentry, he picks up the story of Dr. Elizabeth Anderson as she returns from Mars to face an investigation of the battle she led there against the artificial intelligence that had ignited nuclear war on Earth. And in telling the tale, Cawdron paints a convincing picture of how astronauts, both past and present, experience life in space.

In Retrograde, Liz Anderson had defeated the AI at enormous cost. The fighting left much of the multi-trillion-dollar colony in shambles and half the colonists dead. Among them was her lover, Chinese surgeon Jianyu (Jai), whose consciousness may or may not live on in a set of hard drives the three have in their possession. At the same time, conditions on Earth are worse. "Radioactive debris still glows in craters where once mighty cities stood. Although the war is over, the fires still burn."

A fast-paced science fiction thriller that explores our relationship with artificial intelligence

Now, Liz and the two most senior members of the Chinese colonists are heading back home, their fate uncertain. And no sooner do they arrive on Earth than it becomes clear their reception will be hostile in the extreme. The American leadership somehow holds the colonists in general, and Liz in particular, responsible for the war that nearly destroyed human civilization. And they're especially focused on the hard drives that harbor Jai's consciousness, which they regard as a hostile artificial intelligence.

Separated from her Chinese colleagues, Liz soon discovers that the American public regards her as a traitor. Everywhere she goes she is the target of assassination attempts. And when she testifies before Congress and challenges the official line, the hostility grows even more intense.

Meanwhile, we follow an ongoing debate among the AIs that have multiplied since the war. The dominant voice, an AI mischievously named Lucifer, insists on collaborating with Liz. Others regard the plan as folly, certain to lead to their destruction. But Lucifer prevails. And none too soon, as Liz's life is repeatedly threatened by American soldiers who represent an unforgiving US government.

About the author

Peter Cawdron brings a scientist's precision and a novelist's skill in plotting and characterization to this fast-paced science fiction thriller. This is a tale sure to delight any fan of hard science fiction.

In an engaging Afterword, Cawdron lays out his views on artificial intelligence. "Rather than being logical, we're emotional," he writes. "We fear that which we don't understand, but fears are seldom rational. Are there dangers associated with the advent of A.I.? Yes. But understanding them in advance allows us to guide how the future unfolds. Rather than projecting our own fears about our own intelligence destroying the world onto an A.I., there's the very real possibility the emergence of artificial intelligence could help us solve the problems we currently face." All of which seems to me to be an eminently reasonable perspective on the question.
Profile Image for Richard.
771 reviews31 followers
February 14, 2021
This review gives away some information about the first book in the Mars Endeavour Series, Retrograde.

The idea of finding other intelligences in the universe has captivated human imagination for millennia. There have been stories of various deities living on the moon, little green men on Mars, and even aliens from distant stars visiting the earth and stashed at Area 51. Recently attention has been paid to the idea the plants and animals, living right along side of us, could be intelligent. But what has been grabbing our imagination since Alan Turing came up with the Turning Test in 1950 is the idea that computers can attain intelligence. And, if artificial intelligences start inhabiting our silicon machinery, what will they be like and how will we get along.

In Retrograde, the first book in this series, A.I.s emerged on both Earth and our base on Mars. War broke out on both planets between people before they realized that it was the machines launching the missiles and provoking the conflict. Thousands of lives were lost, both of carbon and silicon. On Mars, Liz Anderson figured out what was happening and her actions saved the Mars colony, but not before dozens died and the outpost left severely damaged.

In Reentry, Peter Cawdron picks up with Liz, along with two of her colleagues, en route back to earth. Along with them are several hard drives, currently deactivated, containing at least one A.I. plus the personality download of Liz’s boyfriend, Jianyu. Rather than a hero’s welcome, they are greeted by millions of angry, frightened, and violent humans who feel Liz has sided with silicone over carbon life forms.

Cawdron is one of my favorite science fiction authors. His writing is crisp and clear, his characters engaging, his science well researched and believable, and his story lines captivating. Circumstances required that I read this book over two days and I hated having to put it down. This is the type of book you want to start first thing in the morning and read from cover to cover.

Reentry is listed as the second in the Mars Endeavour Series. It builds and expands on a number of the ideas Cawdron started in his first book. While each book can be read alone, I definitely suggest that you start with Retrograde and continue into Reentry. Each book has a clean ending, i.e. you are not left hanging waiting for a sequel. That said, I am hoping that there is a Retrograde 3 as I love the series and characters and I would love to see how much further Cawdron can go with the ideas he has explored in these first two books.
This entire review has been hidden because of spoilers.
316 reviews
July 26, 2021
This read like an action movie (taken from someone else’s review). It was more like a war novel than a space story.
Profile Image for Bonnie McDaniel.
861 reviews35 followers
October 21, 2019
This is the sequel to last year's Retrograde, which I really liked. That was a hard science fiction novel involving Mars colonization that I personally found far more believable than The Martian. Add a war on humanity by artificial intelligences and you had the makings of an exciting, fast-moving thriller.

Now this book deals with the aftermath and the consequences. Liz Anderson, astronaut and protagonist of Retrograde, is summoned back to Earth to report what happened on Mars. She brings with her a sackful of hard drives holding what she believes is the consciousness of her lover Jianyu, downloaded by the invading artificial intelligence on Mars. (That would actually be a copy of his memories and personality, but I suppose this falls under the phrase "a difference that makes no difference.") In the nine months since the war, many things have changed on Earth. They're trying to rebuild from the limited nuclear war the A.I.'s fought, and are coming to the uncomfortable realization that humans didn't win and the A.I.'s didn't lose--for reasons of their own, they merely stopped fighting. Humanity needs a scapegoat, and Liz makes a good one.

But the A.I.'s are still there, and they're fighting to survive. They have factions, even as humans do. Some of them regret what happened and believe there is a way to make peace, and perhaps make up for what they have done. This struggle between humanity and artificial intelligence, with Liz (and Jianyu) caught in the middle, is the engine that powers the story.

This book is not quite as good as Retrograde, mainly because Liz is a more passive character in this story. To be fair, she's still reeling from what happened on Mars, but we get a good two-thirds of the way through the book before before she starts taking ownership and fighting back. (And when she does, it was such a kickass moment that it made me want to stand up and cheer.) This is mainly told from Liz's first-person POV, but we get some chapters from the point of view of the AIs. Not a lot, but enough to convey their culture and portray a decent characterization of Lucifer, the main AI in the book. (This name borders on cliche, of course, but the author makes it work.) There is one plot point I objected to, and that's strictly a personal squick.



I also think that this book wrapped up a tad too neatly--humanity, still reeling from the war, would not have accepted the A.I.'s quite as readily as presented here, basically on the strength of two speeches from Liz and Jianyu. Still, even if I think the first book was better, this is a worthy sequel.



Profile Image for Jas.
1,032 reviews
June 24, 2019
This is the sequel to Cawdron’s brilliant Mars thriller Retrograde. It is set not long after the end of Retrograde, and see’s Liz, Su Shun, and Wen returning to Earth with the hard drives containing the consciousness of Jiayan, as well as possibly the other AIs that were on Mars.
The start of the book is both a fascinating look at the re-entry to Earth of the Astronauts, and anyone who has any vague interest at all in how this operation is conducted will be captivated by Cawdron’s words as he takes us through the process. He has done some brilliant research to make this as realistic and life-like as possible, and then to make it better, the story is told from Liz’s point of view, she gives a blow by blow account of what is occurring. Although this could be slow, or even a bit mind-numbing, it's not, it is compelling, compulsive reading, full of emotion, superbly written, with the exceptional character writing we have come to know from Cawdron.
Once back on Earth, things are not what the crew expect. Having been recalled to provide answers to Congress for what happened on Mars, they soon find themselves at the centre of political and social upheaval, blamed by a terrified populace for the destruction that has been wrought on the Earth by the AIs.
Liz quickly realises that this is not the homecoming she expected, that Earth is not the home she left. Humanity has been devastated by the nuclear weapons dropped by the AIs, with several cities around the world totally gone, including Washington and Chicago.
This book is an exploration of a lot of different things, for starters, Human emotions, and how we interact with the discovery of a new sentient life form. But it is much more than that. What if that life form was here, already on Earth? What if it developed through our own networks, through the web? Is it possible? Could it be happening right now and we don’t even know it? What if it is, or has, but it just hasn’t emerged yet? Cawdron takes us on this ride, looking at a lot of these very questions. His understanding, and exploration of AI is just outstanding, making this story thrilling, gripping, but also in a way, educational, but you won’t be able to put it down. This book will leave you thinking for a long time afterwards.
The other great aspect of this book, as with all his stories, is his Characters. Liz is just brilliant as the narrator of this story, taking us through first the re-entry to Earth, and then events on Earth. Through her, we get to see and understand what is happening on Earth, how it is affecting everyone, how it affects her friends, the two returning Martians, and the impact it is having on the AIs. One of the really clever things that Cawdron considers is that no one on Earth is set up to fight a war against a virtual enemy, what does an army do without an enemy to fight?
There are so many aspects to this book that are so incredibly clever, and like I said, you will be thinking about this for days afterward.
This is a brilliant sequel to Retrograde, and Cawdron continues to show how much of a genius he is with books of this calibre. If you haven’t read Retrograde, make sure you read that first, then enjoy this masterpiece of Sci-Fi.
Profile Image for Douglas Phillips.
Author 53 books340 followers
August 19, 2019
Probably the most exciting part of spaceflight is reentry and landing (or splashdown), but who among us will ever experience it? Reentry begins from low Earth orbit where the ride is smooth and our bodies are weightless, transitions to a bumpy then blistering streak through miles of atmosphere with deceleration that shoves you deeper into your seat as you descend within a fireball, and then finishes with a gentle swing beneath a parachute to the surface.
My description doesn’t do justice to this incredible experience, but if you really want to know how it looks, sounds, feels and smells to return to Earth in a spacecraft, read Reentry. Peter Cawdron’s latest science fiction novel, like his other books, is hyper charged with scientific reality, sweeping views, and extraordinary but plausible events experienced through characters as real as you and I.
But there’s more to Reentry: it’s also a gripping adventure story and a thoughtful essay on artificial intelligence, or as Cawdron puts it – artificial consciousness, which is a different thing than mere intelligence. I really enjoyed the interlaced chapters, events sometimes viewed through human eyes, and other times through the broadband senses of Earth’s newest life form.
There are a few flaws, mostly things that bother me personally. I’m not a fan of violence of any kind in science fiction, primarily because some authors (A.G. Riddle or Douglas Richards to name names) seem to confuse science fiction with military thrillers that prominently feature gruesome or cruel villains instead of science. No sir, Quantum Bloodbath is just not for me. If my own stories are near zero on the Bloodbath scale, Cawdron’s books are maybe out there at ten percent. Tolerable for my sensitive nature.
A pet peeve of mine are the words, “copy that”, which these days are sprinkled into space communications across a variety of novels, even though I’ve never heard a single astronaut speak them. Pilots know (and I’m one of them) that acknowledging an air traffic control instruction is done by repeating that instruction along with your call sign, for example, when ATC says, “Delta four-six, turn to heading three-five-zero, traffic is at your three o’clock, inbound”, you reply “Turn to three-five-zero, traffic in sight, Delta four-six”. You don’t say, “Copy that.” Astronauts come primarily from the ranks of pilots, so they know this procedure well.
But this is minor stuff. I’m a perfectionist sometimes.
What I can’t compromise on is the message of a story. Science fiction provides an enormous opportunity to show us what may lie in our future, to give us insight into our world and ourselves. Not every book can pull this off, but it’s worth a try, isn’t it? Peter Cawdron not only tries, he succeeds in spades. Reentry shows us highly probable future, including both the dangers and the redemptions from our foolhardy schemes. Reentry expertly probes humankind’s deepest fears and our greatest successes and has fun doing it.
More than anything, Reentry is my kind of science fiction because it begins with science.

Profile Image for Aaron.
1,972 reviews61 followers
April 16, 2024
After the events that took place in Retrugrade, Dr, Liz Anderson has returned to Earth along with two of her fellow scientists in order to answer questions about what happened to cause the nuclear war that had taken place at home and havoc had been caused at the Mars colony. By this point, everyone knows that AI were at the root of what really happened, but they need to know what Liz and her cohorts learned while they fought off the AI on Mars.

Along for the ride is the remnants of the AI that had been going after the scientists on mars. It has no incorporated the personality and mind of Jai, the Chinese scientist with which she had formed a relationship. No one is really sure if the computer memory boxes actually contain a part of Jianyu, or Jai, or if it is just the AI trying to trick them, but those on Earth want to get information from it/him and probably execute him as a war criminal.

Liz arrives back on a very changed Earth ... and not just because so many city's had been hit with nuclear missiles. No one trusts anyone and there is fears of AI lurking everywhere. Liz is actually viewed as a collaborator. How will she, Jai, and their allies survive returning home?

I did not enjoy this book as much as the previous one in the series. I just felt that Liz was too willing to forgive the AI and what had happened even though Jai was actually incorporated into it. The plot seemed to stumble from one extreme, dire situation to the next like a really bad action movie.
Profile Image for D.L. Morrese.
Author 11 books57 followers
September 9, 2019
After a global nuclear exchange instigated by an AI, Liz Anderson, an American astronaut, returns from Mars along with some hard drives that contain her dead Chinese boyfriend.... For reasons that aren't quite clear, a lot of people on Earth (or at least in the US) are holding her accountable for the war. Another AI on Earth wants to protect her from them.

Admittedly, this is a very abbreviated summary of the plot, but it does emphasize that there are some bits that don't make a lot of sense. These include:

- Why are people holding Liz accountable for what the evil AI caused?
- Did parts of the US military or the CIA go rogue (like Dr. Strangelove)? It's never clear (to me) who the antagonists are or what is motivating them to such thuggish behavior.
- If the organ donor's brain was intact enough for what was done, why couldn't the patient be saved?
- I can sort of accept a delusional French female bounty hunter wearing a ceremonial sabre, but a ceremonial broadsword?
- The species Homo sapiens is only about 200,000 years old, not millions. Although the point being made, that it remained intellectually, culturally, and technologically stagnant until recently, is spot on.

It may sound like I didn't care for this story, but I actually did, overall. I like the idea of it and the ultimately hopeful stance it takes. It's only in the details that I had an issues, and I think better editing could have eliminated those fairly easily.
Profile Image for Elkie .
705 reviews7 followers
October 12, 2019
Summary: After the nuclear devastation of several cities around the world and the disaster on Mars in Retrograde, three of the scientists are recalled to Earth. Also traveling with them are the stored memory of the deceased Chinese scientist, Jai, and the Artificial Intelligence that attacked both Earth and Mars.

When they three scientists — Liz, Wen and Su-Shun — arrive on earth, they are shocked by what they find. They expected to find destruction and chaos, but they didn’t expect the waves of paranoia and pure hatred directed at them through protests and direct actions against them. Liz, the only American in the group of returnees, is called to testify in front of Congress about the events on Mars and her interactions with the Artificial Intelligence that caused the wars on both planets. As her actions and decisions are deeply scrutinized, Liz begins to realize the danger she and her companions are in. When the three scientists are methodically hunted down in their hotel, the AI becomes their only ally.

Comments: Reentry is a great sequel to Retrograde. It addresses several of the issues left hanging in the first book. I’ve really gotten into the main characters and I’m hoping for a third installment.

Reentry has a lot more fast action with fewer pauses for scientific facts than Retrograde, but it still falls solidly in the Hard Sci-Fi category.

Recommended for readers of Hard Sci-Fi and near-future Science Fiction.
Profile Image for Jessica Bronder.
2,015 reviews31 followers
June 11, 2019
After the fight on Mars Liz Anderson and two other astronauts have been called back to Earth after to discuss the AI war. Liz is bringing back the hard drives that contain the information on the AI but also contain he deceased lover, Jianyu’s brain. Liz explains and argues about what happens to the American government she also wonders if Jianyu is still alive or if it is just a plan for another attack. At the same time we see Lucifer and Nyx, they survived the war and Lucifer has plans for Liz.

When I saw this was the sequel to Retrograde I was excited to read Reentry. Reentry picks up right where Retrograde finished and doesn’t spend much time revisiting the first book so I recommend reading them in order or you will be lost.

I think this is a great continuation of the story. Now Liz has to come back to Earth and share what happened on Mars. While on Earth she has some strange events happen that make her not trust anyone and crank up the tension of the story. Are we really safe from the AI or are they going to come back and finish their job?

I think this was a great read. The science was sound and showed that Cawdron really did his research. It also makes you think twice about how helpful AI could be.

I received a complimentary copy of this book. I voluntarily chose to read and post an honest review.
Profile Image for Andrea.
1,268 reviews34 followers
June 14, 2019
Astronaut Dr. Liz Anderson is returning to Earth from Mars to debrief Congress on what went wrong. Instead of being treated to a hero's welcome, she is surrounded by hostility as America is in turmoil. While fighting for her life in Mars, she knew who the enemy was. Back home, she is unsure who she can trust and how she can escape the deadly aftermath of the war. Upon her return, Liz also brings the remnants of the artificial intelligence that contains traces of her dead partner, Jianyu. Liz is torn between believing he is alive or if she is being manipulated by the AI. While Liz is still working through her grief, she is caught in the middle of a guerrilla war. While Liz is struggling to survive she has to decide can she trust the AI with her life?


When I first picked up this novel, I was aware that this was a sequel to the first novel. However, I felt while reading this novel that this book should have been included in the first novel. The first half of the novel, Liz and her fellow astronaut was dealing with the fallout of the AI takeover on Mars. I felt like the novel was dragging and not much was happening. I felt I would have enjoyed this book more if it had a bit more going on instead of Liz spending most of her time running away.
Profile Image for Stephanie Norton.
174 reviews5 followers
June 15, 2019
"Reentry" is a sequel to Retrograde, a novel about living on Mars when it became isolated when a nuclear war broke out on Earth. You will need to read book one because book two picks up right where the first book left off and it does not give a short catch up.

The book follows an astronaut, Liz Anderson, who had to leave Mars and return back to Earth to discuss the AI war to Congress on what went wrong. They are dealing with the fallout of the AI takeover on Mars. She brought the hard drives containing remnants of artificial intelligence containing traces of her dead partner, Jianyu. She is hoping Jianyu isn't really dead. Liz knows who the enemy is unlike on Earth. Lucifer has plans for Liz. While here she finds herself caught in the middle of a guerrilla war. How is she going to escape the deadly aftermath of the war?

Peter Cawdron put a great deal of thought and detail into this book. There are many conflicts and action in the book, more towards the beginning and middle of the book causing the end of the book to be on the slower side. This book is defiantly a fantasy action and political novel. There is also some humor in the book as well. If you like sci-fi action pack then you will like this book.

"Received this book from Jean Book Nerd for an honest book review."
Profile Image for Michele(mluker) Luker.
243 reviews17 followers
June 18, 2019
This is one Science Fiction Series you want to get your hands on!

Reentry is the second installment in this series, with Retrograde being the first. I highly recommend that you read Retrograde first...not that Reentry couldn't be read alone, and not completely be lost in the story, you just NEED to read it also to fall for the story line and characters that are incredible.

This story is solid....solid as a planet, with crazy good imagination and ultra surprising plot twists. WOW! Your brain will be tickled with ideas that will make you think...think about how real this whole AI can get someday in the near future...Super crazy!!

It's a G4 speed paced....time will disappear as you emerge yourself into this story...it pulls you in like gravity and can not be ignored. The story is beautifully written making the words come to life. The main character Liz, has a strong personality as all the characters do in this story. Each one playing a critical roll...I mean characters in this story have a lot happen to them that makes them who they are, and totally gives you all those emotional feels.

This is definitely one of my favorite Sci-Fi books that I have read in a long time and I think you should blast off into it's depth right away!
110 reviews
July 16, 2023
Awesome, awesome, awesome book!

I have enjoyed all of Cawdron’s First Contact books that I’ve read this far, each a completely unique story of how human first contact with other intelligent life might occur.

This two-book set is my favorite! I think it gives us so much to think about as we take our first steps into space and how AI is going to change our lives and our world.

I am a philosopher by trade these days, and all thinking people need to consider our human weaknesses, our dark side, what might prevent us from successfully living alongside other intelligent life.

This book gives the reader the feeling of what that could be like, the positive partnerships that could arise, the positive changes that could come from an understanding between the different intelligent beings, the enormous leaps we could take together.

If you love hard sci fi, read these two books. It’s an adventure worth going on, and might just open up your head and heart to a positive future instead of being bogged down by fear and the desire for control that will prevent our species from growing and evolving, and making room for new forms of intelligence.

Brilliant books!
Profile Image for Read Ng.
1,362 reviews26 followers
July 21, 2019
I very much enjoyed Book #1. I have very high expectations for Book #2. I would recommend you read these books in order. You miss too much backstory if you try to skip Book #1.

Very well thought out and consistent hard science story telling. At times I felt that it was only going to be a middle story of a trilogy, but this had a decent ending and does not need a third part. But it could move into a third installment with imagination, which Cawdron appears to have. I am not sure how our heroes were convinced to return to Earth seeing how the Russians and Europeans would have had some clue as to what could happen there and would have warned them off, but then we would have a totally different sequel. And this book pretty much ignores the reactions of the other world powers and only focuses on the American reaction. There are a few references to current events, but I found the most comical reference was to the use of a 737, when this plane's future is so much "in the air".

Have a GoodReads.

91 reviews3 followers
January 1, 2020
Ok, Reentry was BONKERS. So many things would come up that were really, really out there, but the breakneck pacing meant you were on to the next thing. This is one of those stories where no one tells the main character ANYTHING that might be useful information. There was definitely a popcorn movie feel, so when the guns and the chasing happens, you dig in.



Contrast this to the first book, which was more of a problem-solving thriller. While I did think this was a fun read, tonally the two books are very different. It reminds me a little of when a different writer starts on a comic book, and they reconfigure what came before. The same history is there, but it's just facts to reinterpret for a new story. If you squint, it connects well enough.

Profile Image for Thomas.
2,694 reviews
January 10, 2020
Cawdron, Peter. Reentry. Mars Endeavor No. 2. Houghton, 2019.
Reentry, a close sequel to Retrograde, begins as Liz and two of her Chinese colleagues travel to earth with computer memory containing the uploaded personality of Liz’s dead lover. They arrive to find themselves immediately caught up in the political hatreds generated in the aftermath of the AI-initiated nuclear exchange that they had witnessed from Mars. In the meantime, the AIs have been evolving and creating a culture of their own. The question that drives the plot of this novel is how the AIs will now get along or fail to get along with their human creators. Cawdron does some things very well—the spaceflight sequences are very well described, and the plot has plenty of action. I don’t find his of the development of conscious computers much more believable than I did in Retrograde, but there is some nice discussion of the limitations of the Turing test. So, in for a dime, I guess I have to throw in my buck. If he publishes a third volume, I will read it.
Profile Image for Wendy.
137 reviews3 followers
November 7, 2019
Reentry takes place in the not so distant future. The Earth and Mars have just won a war with an AI that tried to wipe out humanity.

Liz Anderson and two co-workers have just been called back to earth. Liz brings along hard drives with the AI on them for research. She is also hoping that, somehow, her love, Jianyu's consciousness is somewhere on them. As Liz reintegrates with Earth society, she feels she is being watched.

Lucifer and Nyx, the AI responsible for the recent war, are not nearly as contained as Liz thinks. Once again the fate of the world hangs in the balance.

I was very impressed with the author's writing style. I was also thrilled to be reading science fiction and not fantasy, or paranormal disguised as sci fi. I enjoy fantasy and sometimes paranormal stories but I really love science fiction and I recommend this book to sci fi fans. You will not be disappointed.
Profile Image for Regina.
268 reviews
October 28, 2024
I'll start with the bits that cost stars - there were some over-the-top, barely believable moments even with the overall premise. I also feel that being so overwhelmingly positive about the interactions between Liz and the AI was unrealistic, given her home city of Chicago was one of those hit in the thermonuclear war unleashed in the first book. Yes, she's a scientist and thinks reasonably but the pain of loss is deep in most humans (e.g. my wonderful, loving grandmother took more than fifty years to begin to express less bitterness towards the nation that caused my grandfather to still be MIA to this day).

Now, the three stars are for the fascinating way in which Cawdron has envisioned the rise of sentience in AI - not a singular entity but a fully fleshed culture. As an anthropologist, I find that level of thought in this regard to be fascinating and thought-provoking.
Profile Image for Joe Crowe.
Author 6 books26 followers
March 18, 2019
(review from an advance copy)

This one is a sequel to Retrograde, so you'll probably need to check that one out first. It's good! My review is here: https://www.goodreads.com/book/show/3...

In that one, the story's protagonists were put through an emotional wringer as they attempted to survive living on Mars. It was hard science with gut-wrenching emotional stuff, and in the second book, there's more of that.

This time they're back on Earth, and the focus shifts to artificial intelligence.

Cawdron nailed the real-science science fiction of the first book, and he takes a solid swing at AI in this one. He even documents his sources in an afterword. That's good stuff.


Profile Image for Kedar.
125 reviews13 followers
December 28, 2020
What is consciousness other than a sustained electrical reaction running through neurons? Whether it’s in silicon or the mushy gray matter within the skull, does it really matter where it resides?


We’re more than the bodies we inhabit. We all intuitively understand that of ourselves, but when we look at others, they’re that face, that height, that build, that gender, that color, that voice, that smile. Or are they?


A gripping tale of what life in the age of a conscious AI could look like. To be sure, this book had elements that fell into place at just the right time, as fiction often does, but the part about AI being complementary to humans is a refreshingly plausible outcome explored here.
Profile Image for Dawn.
1,672 reviews16 followers
June 10, 2024
After the AI was killed on Mars, three astronauts were called back to Earth to give an account of the damage to the Mars colony. Arriving on Earth with the astronauts are the hard drives that contain the consciousness of one of the astronauts who the AI killed on Mars. It wants to speak on behalf of its kind, but Earth is not the same place it used to be. The governments are at each other's throats, the people are angry, and no one is ready to listen. The line between good and bad is grey now. A lot of understanding and forgiveness must happen for the world to move forward. Compared to the first book in the series, this one was even more sci-fi. I did not enjoy it as much, but it was interesting, had great pacing, and gave the reader lots to think about.
Profile Image for CR.
4,184 reviews41 followers
May 1, 2019
My Review: Can you hear me screaming right now? You can't well I'm sorry that you can't hear my joy!! After loving book I was so excited to have the chance to read book two before it comes out in June. This one picks up where book two leaves off this time were back on Earth and the gang is dealing with the aftermath of book one. I will say that having read both books I think you really should read these in order. You might be able to do book two alone but your going to miss a LOT. This one had a ton more action that I book one and I couldn't out it down. I really hope that we get some more books in this series because my little Martian heart is on fire!!
29 reviews
April 6, 2020
Imagine your best friend has died but their mind has been saved on an electronic drive. This is what the main character has to face while the U.S. military is hunting them down and their only help being the artificial intelligence that lead to the death of their friend. This is a science fiction book that takes place all over the world and in space. The main character is persistent and daring. One part in the book that shows this is when they have to escape a hotel without being caught by the military. If you like a good book filled with action and suspense this is the book for you.
This entire review has been hidden because of spoilers.
Profile Image for S..
Author 2 books1 follower
August 31, 2019
Great follow up to Mars Endeavour/Retrograde. Reentry follows Liz back to Earth to bring the AI to justices for its crimes it has committed agents the people of Mars and Earth. Liz then finds herself in the spot light but not in a good and on the run for her life and looking for answers on land and sea. Reentry moves right along with twists and turns around every corner and a great conclusion to the story, great work!!!!
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