Nebulis

Black Hole Radio #6

by Ann Birdgenaw, Afzal Khan (Illustrator)

Stay tuned for another exciting episode of Black Hole Radio–Nebulis!

Hawk, Matt and Celeste and all the sixth grade are going on a field trip to . . . the Planetarium! It’s going to be so cool because Matt has permission to make a rap music video in the interactive space room. What could go wrong? Plenty when Hawk accidentally pushes the ON button on the black hole radio in his backpack! Big Yikes! The friends are swept away to Planet Nebulis during a deadly dust storm. Luckily, they discover an oasis. It’s a beautiful bioluminescent jungle, with enormous tree, flowers—and plant people. They find out that the planet’s life crystal needs to be reset to restore balance to the planet and their Protective Dome. Can the friends help them to access the crystal buried at the core of the planet? And will the nasty space pirates find a way in before they can fix it? Stay tuned!

“Young readers will be attracted by the action and extraordinary environment, but underlying the adventure is a sense of passion about seeing things differently and helping others do the same.”
—Midwest Book Review

"If you have young readers (ages 8-12) who like stories with wild and crazy adventures, check out the Black Hole Radio series."
—Feathered Quill Book Review

“Black Hole Radio is a thoughtful read that blends science fiction with themes children can relate to. This book is a delightful choice for fans of middle-grade fiction and anyone who enjoys adventurous storytelling."
–Readers' Favorite Review

Genres: Childrens

134 pages, Kindle Edition

Published January 7, 2026

About the author

Aurora Award nominee for Best Young Adult Novel - Ka'Azula, (2023) and retired librarian. Ann always wanted to write a book of her own. She was inspired to write this story by a strange beeping coming from a box in her garage. When COVID-19 hit Canada and everyone was in quarantine or lock down, she had lots of time to imagine being sucked through a wormhole to other planets and what wonderful things she might find there. She is also the author of the soon to be published, humorous picture book titled, "The Squirrel Show". Stay tuned!

Ann lives in Montreal, Quebec, Canada with her family and two pups: Milo and Sheba.

https://awesomegang.com/?s=ann+birdgenaw

Reviews

[Laura Koerber · Rating 4 out of 5]

If I was still teaching, I would buy this book for my middle school classroom. It's a good book for reluctant or slow readers because the vocabulary is limited and the story is very straight-forward with lots of action. It isn't subtle or character-driven; this book is intended to be light fun, and it is. The genre is sci-fi.

[Chelsea O'Hara · Rating 4 out of 5]

This was a fun and imaginative sci-fi read. The concept is creative and easy to follow, and the story keeps a good pace that younger readers will likely enjoy. I also liked the illustrations throughout the book. They added a nice visual element and helped bring some of the moments to life.

One line that really captured the sense of wonder in the story for me was:
"There are too many celestial things to look at."

Overall, an enjoyable and accessible space adventure for younger readers who enjoy imaginative worlds and light sci-fi themes.

[Peter McKenna · Rating 4 out of 5]

"Black Hole Radio - Nebulis" is a fun-filled adventure for school-age readers. This book offers plenty of heart along with a positive message about helping others. The cast of endearing and at times silly characters is easy to root for, and the action-packed plot keeps the story moving at a lively pace, encouraging young readers to let their imaginations run wild. Charming illustrations throughout help bring the story to life and make the reading experience even more engaging.

[Loralee · Rating 5 out of 5]

I was very excited to read this newest book in the Black Hole Radio series. I've read and enjoyed the other books that came before it. In this installment, Matt, Celeste, Hawk, and their little pal Sploot are off on an adventure. It starts without the kids expecting much, looking forward to a trip to the planetarium, and then the group is off! This time, they find themselves on Planet Nebulis where they befriend two plantish creatures, Giant and Pea. Pea is sick, and they need to get it help. They have to deal with space pirates, an AI entity that is sometimes cooperative and other times not, and a crystal that is dying, but is needed to maintain the balance of the world. Will the kids be able to restore order?

This was a very enjoyable tale, and kids as well as adults who enjoy middle grade adventures, would enjoy it.

[Clay Smith · Rating 4 out of 5]

Nebulis is a fun-easy read, perfect for elementary school age children. This is the second book I've read in the series, and I've been consistently impressed with Birdgenaw's consistent characterization and fun plots. It's exactly the kind of book that I would have loved as a child, and it's the kind of thing that's going to help stoke an early love of reading in a lot of kids. Keep it up, Ann!

[Allen Dean · Rating 4 out of 5]

Every generation needs its gateway drug into science fiction. Not the hard stuff — not yet — but the first hit of wonder: the moment a young reader realizes that a story can take you somewhere impossible and make you believe it matters. Ann Birdgenaw's *Black Hole Radio* series understands this assignment, and *Nebulis*, its latest installment, delivers it with infectious energy and a quiet intelligence that earns more respect than its breezy surface might suggest.

The setup is pure middle-grade joy. Hawk — named, with endearing earnestness, after Stephen Hawking — along with best friends Celeste and Matt, is once again pulled through a wormhole by the titular Black Hole Radio, this time landing on the planet Nebulis. It is a world of bioluminescent jungles, enormous trees, unusual flora, and plant people — gentle giants who serve as caretakers of an artificially maintained ecosystem. But the cosmic cloud that shields Nebulis from external threats is failing, the planet's life-crystal has gone dark, and space pirates are circling like predators sensing weakness. The children must descend toward the planet's core to reboot the system, navigating volcanic chutes and hostile terrain in a journey that owes a cheerful debt to Verne's subterranean classic.

Birdgenaw writes in first person, present tense — a choice that keeps the narrative immediate and propulsive, well suited to a readership that processes story the way it processes life: in the urgent now. The pacing is relentless without being exhausting, and the author has a gift for balancing action sequences with moments of humor and warmth. Hawk's voice is engaging, the friendship dynamics feel authentic, and the space ferret Sploot provides exactly the kind of loyal, slightly absurd companion that young readers will adore and adult readers will tolerate with a smile.

What lifts the book above simple adventure is its thematic undertow. Nebulis, with its failing protective shield and dying ecosystem, reads as a gentle parallel for our own fragile planet — an ecological parable threaded lightly beneath the action, never didactic, always accessible. The science factoids, delivered through Hawk's grandfather's memories, function as breadcrumbs of genuine learning scattered along an entertainment trail. There is a glossary at the back mixing real and invented terms side by side — a small touch that speaks to Birdgenaw's understanding that the boundary between the known and the imagined is exactly where young scientific curiosity lives.

The book is not without its imperfections. The prose, while energetic, occasionally stumbles on grammatical unevenness that a sharper editorial pass would have caught. The antagonists — space pirates in the classic mold — serve their narrative function without ever becoming particularly memorable; they are menace by appointment rather than by character. And the story's moral architecture, while admirable in its emphasis on teamwork, self-sacrifice, and courage, sometimes leans toward the explicit where implication would trust the reader more.

But these are small complaints about a book that knows exactly what it wants to be and executes with conviction. *Nebulis* is a fast, inventive, generous piece of children's science fiction — the kind of story that sends an eight-year-old to bed thinking about wormholes and wakes them up wanting to know how crystals actually work. In a literary landscape where young readers are offered no shortage of dystopian anxiety, Birdgenaw offers something rarer: optimism backed by imagination, and the quiet insistence that kids working together can, in fact, save a world.

[K · Rating 4 out of 5]

A great gift option for kids

This is a cute sci-fi book where three sixth graders get to travel to another planet with a radio, that belonged to one of their grandfathers. What follows after that is the story. The plot is definitely old wine in a new bottle, but the author has added enough originality in terms of the world beings and other accessories, such as luminous stones, that keep the reader interested. The language is simple and clean, and the author has also added a glossary to help the kids with certain words. Another fun cooking activity at the end is also a cherry on top. Loved the illustrations too!
Being a children's book, I was wondering about the use of the ‘they’ pronoun for Sploot in the book. (Not a hater or anything, but I feel that worrying about pronouns shouldn't even be a thing for kids, especially sixth graders.) Otherwise, the characters are designed very well. The kids actually behave like kids, and each of them has their own personality and interests, which makes them easy to distinguish. I also thought every character in the book had believable arc.
That said, I did find some parts of the plot a little too easy. The process of changing the crystal and evading the space pirates happens quite smoothly, considering the danger involved. Similarly, the explanation given by the advanced planetary beings about their inability to replace the crystal because of its size felt a little questionable. If they can create something as advanced as DAR, couldn't they also create a mini-robot to handle it? Just saying!

My Score Chart
Characters: 5/5 all the characters are beautifully written
Plot: 3/5 very predictable
World-building: 5/5 Very innovative
Writing: 4/5 Simple, clean and kid friendly (I was a little confused about using ‘they’ pronoun in a kid’s book though)
Originality: 3.5/5 Similar to any children's sci-fi adventures, but with enough original elements to make it interesting.
Overall: 4/5 from me. Will definitely recommend to kids.

[Evie Rey · Rating 5 out of 5]

This is a brand-new author for me, so I wasn’t sure what to expect, but I really enjoyed this book. Black Hole Radio - Nebulis is a sci-fi novel for middle schoolers, but it was still entertaining enough to keep me interested. I’m even considering gifting it to my goddaughter for her birthday. I also thought the illustrations were pretty cool. I found myself studying some of them longer than I probably should have, LOL. My favorite was the one in Chapter 15, “Statue of Venus.”

The friendships were one of my favorite parts. Seeing the characters connect gave the story a lot of heart. Their interactions felt genuine, from their jokes to their loyalty. They weren’t just background characters...they seemed like real kids you could imagine hanging out, getting curious, and getting into trouble together, just like my own kids and their friends.

I also liked how the story unfolded. You discover things alongside the characters. Each new detail kept me wanting to read more. The story also touches on feelings like sadness, loneliness, curiosity, and the desire to connect, which made it feel more meaningful.

I also have to mention Sploot! That little alien is both weird and funny, and added warmth and balance to the story. Somehow, Sploot made the group dynamic even better.

Overall, I really enjoyed this book. I thought it had a strong emotional core, which is my favorite kind of sci-fi. If your middle schoolers like character-driven stories with mystery, strong friendships, and a touch of cosmic weirdness, I think you’ll enjoy this one too.

[Balroop Singh · Rating 5 out of 5]

I have read all the books in the Black Hole series and therefore immensely enjoyed this one. I felt like meeting the well-known adventurous friends and knew that they would take me to another planet for a fun ride. Hawk takes his Black Hole Radio on the field trip to the planetarium and is suddenly pulled through a wormhole, along with Matt, Celeste, and their newest companion Sploot. This time, they land on the planet Nebulis, which looks like a hot, humid, giant rainforest. They meet a strange green creature who barely seems to be breathing.

True to her style, Birdgnaw’s breathtaking pace of storytelling, without any superfluous details, captures you the moment Hawk and his friends land on the planet. The beauty of the jungle, where plants glow softly in blues and greens and the flowers shimmer like glass, the description of the creatures they meet and their journey through the “volcanic tubes” exhibit the superb creativity of Birdgnaw. The challenge before Hawk and his friends is as massive as the Giant who guides them toward the planet’s core to re-set the life-crystal. Soon they run into serious trouble. Will they succeed in their mission? This question increases your reading speed.

The illustrations are catchy for young children, and the fun element never wanes till the end. I finished this book in one sitting; such is the magic of Birdgnaw’s captivating writing style. Highly recommended.
…

[David Woods · Rating 4 out of 5]

Tune in to Planet Nebulis

Another fast, fun instalment in the Black Hole Radio series. Hawk (yes – named after Stephen Hawking), Matt and Celeste are back, and this time a school field trip goes spectacularly off-course when the black hole radio whisks them to the troubled planet Nebulis.

Nebulis feels like a clever parallel for our own fragile world – with a protective shield breaking down, except instead of UV rays, it’s space pirates threatening to storm in through the failing cosmic cloud that envelops the sphere. Time for our three heroes to save the planet. The eco-thread runs lightly beneath the action, never preachy, always accessible.

As ever, Birdgenaw blends adventure with science factoids, delivered via Hawk’s Grandpa’s memories. There’s also a nod to Journey to the Centre of the Earth, bringing a sci-fi classic into the orbit of today’s screen-time generation, complete with a subterranean detour down a volcanic chute.

Social media, rap videos and playground banter keep it contemporary. It’s fast-paced, inventive and packed with a fun glossary at the end – both real and made-up terms, side by side. A lively sci-fi adventure for 8-12s who like action with a dash of relevant science woven in.

[Amber Daulton · Rating 4 out of 5]

Having read the other Black Hole Radio books, I was happy to give Nebulis a chance. It’s an imaginative science-fiction adventure filled with humor, friendship, and excitement. Hawk, Matt, and Celeste are back with their alien friend Sploot as they travel to yet another world that needs saving.
Hawk’s first-person narration is energetic, and he sounds just like a sixth grader. The main theme of the book is courage, loyalty, and helping others, which adults and kids alike can relate to. That stated, the pacing could’ve been tighter at times and the sentence structure less short and choppy. However, this book is intended for kids, not adults, so I think it’s just right for a younger audience.
Black Hole Radio: Nebulis is a fun book with creative worldbuilding and a fast-moving plot that should appeal to middle-grade readers who enjoy space adventures, unusual creatures, and stories about friends working together to solve problems. It’s an entertaining and imaginative journey!
4 Stars

[Lynn Helton · Rating 4 out of 5]

This is another entertaining addition to the sci-fi series "Black Hole Radio". In this 6th book of the series, the radio takes Hawk, Celeste, and Matt on a journey to a planet that's a strange mix of desert and jungle, inhabited by plant people.

With an important task for the characters to accomplish and a threat of space pirates, the story draws the reader right in. It moves along at a great pace as the children discover aspects of the strange world and learn how they can help the inhabitants. Fun extra epilogues help wrap things up and even provide a recipe to try. And a glossary at the end provides some terms to learn.

Overall, this is an engaging sci-fi adventure story, well-suited for its intended middle-grade readers. An enjoyable read!

[James Joseph · Rating 5 out of 5]

Nebulis is another wild ride of a sci-fi children’s book in the Black Hole Radio Series. This time, Hawk, Matt and Celeste are whisked off to a planet with tropical forests and plant people. Called Nebulis because it is enveloped by a cosmic cloud, which safeguards it from attacks by space pirates. But the buffer is breaking down, smothering the planet and allowing the pirates easy access. Our heroes are needed to descend towards the planet’s core to reactivate the shield, while avoiding the nasty pirates. A perfect book for kids aged 7 to 12 looking for non-stop action, heart-thumping adventure, lots of laughs and a story where kids working together can make a difference.

[Lonnie Webb · Rating 3 out of 5]

A good YA yarn

Ann has delivered a wonderful sci-fi yarn hindered by some noticeable grammatical mistakes. That still leaves a three star YA story.
The story carries a good bit of “the Message” with it in that it kind of hammers the reader with they/thems. I”m not a hater, more of a leave-them-be-er, but in the States we have a shocking trend of them/them school deletions. For that reason I can’t recommend it for elementary. Please understand I say that with sadness.
The science fiction elements are imaginative and fun. The authors courage and compassion deserve admiration even tho I greatly encourage a sound editor come on the scene.

[Eric Gibson · Rating 5 out of 5]

Hawk, with his best friends Celeste and Matt, are reluctant heroes with powers and a gateway to other worlds. Joined by their space ferret Sploot, this episode is from Hawk's viewpoint, and deals with helping and heroism. A green giant and his child are caretakers of an artificially maintained planet and they need someone to reboot the system. This one has space pirate antagonists, though there isn't much violence, just general menace. Nebulis is a straightforward adventure, and it serves to reinforce the morality that these characters always display.
First person, present tense, and well edited without noticeable errors.

[Linda Sanchez · Rating 5 out of 5]

I’ve read several of the Black Hole Radio books, and I always enjoy the creativity in these stories. The different planets, unique creatures, and imaginative settings keep things interesting.
This one was a fun adventure, especially with the visit to Nebulis and everything that comes with it. The story moves quickly and keeps younger readers engaged while still weaving in some meaningful lessons along the way.
I also liked seeing one of my favorite characters, Sploot, again. That was a nice touch.
Overall, a fun and imaginative read for kids who enjoy action, sci-fi, and a little bit of heart mixed in.

[Christine Hees · Rating 5 out of 5]

Black Hole Radio: Nebulis takes the classic Magic Tree House formula (kids, a portal, a big adventure) and gives it a modern upgrade with snappier dialogue, more personality, and richer language. Hawk, Matt, and Celeste run a secret space club with a homemade radio that flings them through wormholes, and their stowaway alien sidekick, Sploot, steals every scene.

What makes it work so well is how relatable it feels: crushes, viral videos, anxiety, and grief show up right alongside pyramid traps, dying planets, and an AI companion facing a heartbreaking sacrifice. Lots of twists and genuine heart. A great pick for kids who've outgrown Magic Tree House. Highly recommend!

[P. Portraits · Rating 4 out of 5]

Alien Adventure

The first part of the story takes a little while to get going, and although I particularly enjoyed the rap, I was relieved when the pirates turned up and added a satisfying sense of threat to the adventure. What made the story work, for me, was that it might be a video game, and there are references to Minecraft and applying how playing that game might work to advantage the characters' predicaments. I think the age group this is appealing to will like that.

The fun facts are useful, but I prefer the fiction, and I think further emphasis on the dramatic scenes would make it an even more enjoyable read than it already is.

[Terry Birdgenaw · Rating 5 out of 5]

Nebulis is the sixth book in the Black Hole Radio Series and is another stellar contribution. In this episode, our heroes visit a planet with dense jungles and inhabitants that resemble plants. The planet is engulfed in a nebula which keeps out space pirates. When the cosmic cloud breaks down, the pirates swarm. Hawk, Matt and Celeste, along with their friend Sploot, need to avoid the pirates and descend deep underground to repair the crystal that powers the protective nebula. Seven to 12-year-old kids will really enjoy this humorous, sci-fi/action/adventure.

[Susie Smith · Rating 5 out of 5]

Green Aliens & Greedy Pirates

Another adventure for Matt, Hawk, & Celeste when the Black Hole Radio whisky them thru a wormhole to the planet Nebulis.

A Green Alien guides the inside a huge Pyramid helping them avoid poisonous planets and attacking pirates.

But the planet's crystal is dead and the planet is dying. Green is too big to go thru the shuts to the chamber to restart the crystal. So Hawk, Matt, & Celeste volunteer.

Follow them on their exciting adventure.

[Soph · Rating 5 out of 5]

Loved this book!
Another fun adventure for Hawk, Matt and Celeste. Nebulis continues the wormhole travel to a planet of plant people and glowing jungles. Lots of scifi action for young readers 8-12.