Jump to ratings and reviews
Rate this book

What They Don't Know

Rate this book
A picture-perfect suburban life fractures . . . and a darker reality bubbles beneath the surface.

Mona Ellison's life is as perfect as the porcelain dolls lined up on her shelves. She has a successful husband, a loving son, a beautiful home, and a supportive group of girlfriends ever ready for their weekly wine night.

But when Mona’s son gets entangled with the wrong crowd and runs away from home, her blissful suburban world begins to unravel. She tells her friends that boys will be boys, that he’ll be back as soon as his money runs dry . . . but deep down she knows there’s something else going on.

Then the police show up at Mona’s door. A young girl has turned up dead in their quiet town, and her missing son is the prime suspect.

Determined to reunite with her son and prove his innocence, Mona follows an increasingly cryptic trail of clues on social media, uncovering a sinister side of suburbia and unveiling lies and betrayal from those she trusted most. And as Mona spirals further from her once cozy reality, a devastating revelation shatters everything she thought she knew. Now the only thing she’s sure of is that she can’t trust anyone . . . not even herself.

With unrelenting psychological suspense and a wicked twist, What They Don’t Know marries small-town thriller and domestic mystery—suburban paranoia at its best.

240 pages, Kindle Edition

First published May 17, 2022

9 people are currently reading
3724 people want to read

About the author

Susan Furlong

32 books835 followers

Susan Furlong grew up in North Dakota where she spent long winters at her local library scouring the shelves for mysteries to read. Now, she lives in Illinois with her husband and children and writes mysteries of all types. She has over a dozen published novels and her work has earned a spot in the New York Times list of top crime fiction books of the year. When not writing, she volunteers at her church and spends time hiking and fishing.


To learn more about her writing, visit her website at www.susanfurlong.com

BookBub @SusanFurlongAuthor
Twitter: @Furlong_Sue
FB: Susan Furlong - Author
Instagram: SusanFurlong
Pinterest: Susan Furlong - Author

Follow me on BookBub: https://www.bookbub.com/authors/susan...



Writing as: Susan Furlong/Lucy Arlington

Ratings & Reviews

What do you think?
Rate this book

Friends & Following

Create a free account to discover what your friends think of this book!

Community Reviews

5 stars
89 (26%)
4 stars
137 (40%)
3 stars
91 (26%)
2 stars
17 (5%)
1 star
6 (1%)
Displaying 1 - 30 of 93 reviews
Profile Image for Carrie Schmidt.
Author 1 book517 followers
June 6, 2022
Let me preface this review by advising you to read this with the lights on & with enough time to finish it in one sitting. Because Furlong has created a story that will have you questioning everything, looking over your shoulder, jumping at night sounds, and devouring every word. You won’t want to put it down, and the pacing is so well-timed that it feel like the pages have passed in a blink

Psychological-thriller-slash-domestic-suspense is one of my favorite genres when done well. After all, it has to be a pretty amazing novel for me to not miss the romance haha. (#priorities) I especially love it when you’re not sure whether the narrator can be trusted or not because it keeps me all twisted up for the duration of the story, mind racing as I try to figure it all out. What They Don’t Know is one such novel, and I loved every minute of this twisty puzzle.

The characters in this book are deliciously layered and deceptively flawed, and even the most seemingly-insignificant player has an important role in this drama. At the core of the suspense are some underlying questions – namely, who can be trusted and what can be trusted. Mona’s grip on reality fades in and out (or does it?), her friends all have buried secrets (or do they?), her son is missing (is he really?) and her husband is overmedicating her (are we sure?). Furlong has done a masterful job of keeping us twisted and tumbled inside out and upside down from the first word until the book’s exhilarating final chapters.

Bottom Line: What They Don’t Know by Susan Furlong is a delightfully creepy, atmospheric roller coaster ride through small town suburbia, a little bit Desperate Housewives and a little bit Rear Window. Whose reality can be trusted? Who will remain standing when it’s all over? If you’re a fan of Lisa Jewell, Carrie Stuart Parks, or Jaime Jo Wright, you’ll want to read this book! (but please see my reviewer’s note below)

(I voluntarily reviewed a complimentary copy of this book)

Reviewer’s Note: Readers may want to be aware that there is some mild cursing throughout this novel, as well as a stronger word used a couple of times. Otherwise, I would consider it a clean novel.

first reviewed at Reading Is My SuperPower
Profile Image for Linda.
708 reviews38 followers
March 9, 2022
This book was a real whodunnit. The twists and turns left your head spinning. A girl is found dead and the road to finding her killer is long and winding. This is a must read novel if you like a Law and Order type of story. This is my first book by this other but certainly not my last.
Profile Image for Prakarsha Pilla.
137 reviews5 followers
May 21, 2022
What they don’t know by Susan Furlong

Mona Ellison’s son is gone from home. She thought it was a teenager’s whim, until it wasn’t. Mia Jones is found dead and her son’s connection with her is public. She decided to clear her son’s name for which she has to find him. In her search for a simple truth, she found many secrets which left her with nobody to trust. Where is her son? Who killed Mia Jones? Who, in her family and friends, is really helping her?

The story is a perfect psychological suspense. Mona is obsessed with her porcelain dolls and often loses herself under the influence of her medication. Her husband Ben is a psychologist himself. The author delves deep into human psychology and what better way than to entangle it with crime. There are many twists in the story but the last one is my favorite.

The English is quite simple and can be read by anyone. However, it might seem verbose unless the genre interests you. The story proceeds quite slowly and I couldn’t read it in one go. It should be read attentively and carefully to enjoy the crux.

What I specifically liked about the book was the character of Mona Ellison. She runs the story and balances herself through every catastrophe. She is one of the most complex mom characters I read. How far a mom would go to clear her son’s name and get him back home is inspiring.

I would recommend this book to anyone interested in psychological suspense and has read this genre earlier too. Would not recommend to anyone who wants a quick and short read.

I received a review copy and I am posting my review voluntarily.

Prakarsha.
Profile Image for Nanasbookreviews.
1,837 reviews54 followers
February 17, 2022
I received an ARC in exchange for an honest review.

What they don't know by Susan Furlong

This book rocked my world. One twist follows another until the big finale. It's a psychological suspense that begins with a tragic scene and was slowly becoming more intense by the minute. It is divided into four parts, the first is about stating facts, and the other three is a step-by-step revelation of what happened. I am astonished by the way it is written and how the plot changes
in a natural yet surprising way. The characters are very few but each one has a crucial part in the storyline. Mona is my favorite by far. Her "broken" state of mind combined with her tragedy makes her the perfect lovable victim. It's so easy to feel her every emotion and connect with her. Not in a million years could I have ever imagined the outcome of this situation.

I am pretty sure that I won't forget this book, it surely made an impact on me. I highly recommend you to read this if you love suburban psychological suspense novels. I will rate it with 5 stars.
Profile Image for Taryn.
1,114 reviews32 followers
May 17, 2022
From the outside it looks as if Mona Ellison has a life that couldn't be more perfect. A successful husband, a wonderful son, and a group of friends that has always stood beside one another. Once you get a look into her life though you see the cracks. A son who has run away, A husband who works all the time, and friends who aren't quite as loyal as they seem. The cracks come wide open when the police show up at Mona's door asking about a young woman who has been found dead, her son, and a car they use to own. Mona doesn't believe her son could hurt anyone and goes on a journey to prove his innocence. Follow along as each chapter takes you on a ride full of twists and turns that will have you guessing until the end!
Profile Image for Bev.
3,275 reviews98 followers
May 17, 2022
As with all of Susan's books I have read, this one did not disappoint! A very good story about a mother's love and what she will go through to help one of her children. But when she starts to question her own thinking, can she continue? I voluntarily reviewed an ARC of this book.
Profile Image for Cover Lover Book Review.
1,488 reviews86 followers
August 31, 2022
Wow! What They Don’t Know is certainly out of my normal reading genres. I wanted to venture out to a new author (Susan Furlong) and a rarely visited genre, so I chose this book. Now I know why I don’t read a lot in the psychological thriller category. I get creeped out easily! But wow. In a good way.

I love a story that makes me feel something – whether happy, sad, sympathetic, insightful, or even fearful. And seeing the world through Mona’s eyes made me feel a lot. Porcelain dolls have always given me the heebie-jeebies, so that mixed with a murdered woman, a questionable suspect, and the psychological undertones made me sleep with a nightlight.

This is a nervy, unnerving, twisting, intriguing, page-turning tale that grabs you from the first page and doesn’t let loose. I questioned everything and was kept guessing. I enjoyed the author’s unique writing style and hope to revisit her writing again. (Eek. Did I just say that?)

First Line: The predawn light casts a dismal gray through the barn as Detective Lucas Reyes steps inside and squints to gain focus, his gaze landing first on a rusted steel harrow in the corner, its tines like wet dragon teeth, then on the crime scene techs placing numbered markers, snapping photos, documenting and bagging evidence.
Genre: Domestic/Psychological Thriller
Page Count: 286

Disclosure: #CoverLoverBookReview received a complimentary copy of this book.
Profile Image for Elaine .
1,047 reviews64 followers
January 12, 2023
What they Don't know.
Susan Furlong.

Suspense thriller, A real twister. This was totally A enthralling book. You just never know. As they The title says... What they don't know.. I must say perfect title for a perfect story.


A mother who's lost her child...has her porcelain dolls... She has her husband and Well her prescriptions he prescribes because well hes a doctor... And the best friends who live right across the street... Nothing happens in this suburban neighborhood without everyone knowing everything or do they... Even murder... Sometimes it's dark. And you don't always see what you think you're seeing.. Or do you.

Sometimes keeping secrets, Until the very end. Are what makes everyone's life better Or just maybe your own.


Well I must saythis was a very good book. One that will have you guessing till the very last page..
When I thought I had a few things figured out.. Got to the ending and realized I was wrong.. such a good book.
Thank you Susan Furlong.
Profile Image for Linda.
Author 14 books799 followers
June 5, 2022
I stayed up way past my bedtime reading this stunning psychological thriller, all while trying to shake off the shivers crawling down my spine. Susan Furlong is a master at her craft, and this superbly written novel is the proof. Just when I thought I’d peeled away all the layers and figured out the ending, along came a final and shocking twist that rocked me to the core. A ten-star read all the way!
Profile Image for Ferne (Enthusiastic Reader).
1,487 reviews48 followers
January 3, 2024
Mona Ellison is hosting the last book club evening in her suburban home with her dearest friends, all neighbors. The last time book club members are together as Mona and her husband are moving to the city. The women are worried about Mona, but everyone hopes the move will be a new beginning.

A page-turning ride of psychological suspense! Have you ever cruised down the highway, and without warning, the lanes are blocked, and everyone is directed to exit with those directing, giving signs it is imperative to comply? Yet, there is no indication anything is amiss up ahead. At that very moment, I felt adept in knowledge of the plot; the author directs the ride with urgency to the exit with a resounding twisted turn, building another layer of intrigue into the story. I loved the intensity streaming through the chapters to the very last line!

Thank you to Susan Furlong for selecting me as the Tag-a-Library-Contest winner on Instagram and inviting me to select one of your stand-alone titles. The novel was beyond all anticipation in an extraordinary way! Thank you!
Profile Image for Shelly.
Author 2 books37 followers
May 8, 2022
Prepare for a rollercoaster ride of events that leave your hair standing on end, nerves on edge, and a deep-seeded sense of angst with this enthralling read from Susan Furlong!

I love a book that crawls under your skin, leaving a tingly, uneasy feeling that you can't take anything at face value. This book fulfills everything I look for in a psychological thriller! The sunshine-y exterior of this suburban neighborhood is quickly tarnished, yet you'll find yourself questioning reactions and motives of every character.

Mona is a complex, in-depth character who I enjoyed climbing inside her mind (even though I was disturbed by the doll obsession). Something is off and not in a good way. Her mental state, along with the medications, helps to twist you into caring, but being cautiously wary.

Furlong's ability to keep you hooked is astounding. The pacing is perfectly in sync, kicking up the uneasy feelings bit by bit. The family dynamics are twisted and if you're not paying close attention, you'll miss small details that turn into big details later. There were several times that I went back to read more slowly to absorb it all. If this were a movie, I wouldn't turn the lights off for this one!

I received a complimentary copy for reviewing purposes. All opinions are my own.

Profile Image for Erika Bucci | erikalaceyreads.
214 reviews15 followers
June 15, 2022
This book is broken in 4 parts and told in 1st person from Mona’s POV with some 3rd person from Detective Reyes POV. This was a great psychological thriller. The author did a fantastic job of making me feel like I was living in the mind of the main character (who is not the most mentally stable). There were a lot of unpredictable twists and turns that I didn’t see coming at all! Especially the very end. I can’t wait to see what else this author comes out with! If you like psychological domestic thrillers, creepy dolls and unreliable narrators then definitely check this book out!
1 review1 follower
January 13, 2023
Twists and turns with every chapter. I had a haunch, but it kept me guessing up to the final few chapters!
162 reviews1 follower
January 4, 2023
I'm genuinely confused if I read a different book than these other reviews because absolutely nothing happened in this book
Profile Image for Lisa.
143 reviews4 followers
Read
November 6, 2023
I plowed through this in a weekend. It was on audio, and I wasn't crazy about narrator but suspense was well done. Author did great job of keeping me listening.
Profile Image for Bookreporter.com Mystery & Thriller.
2,650 reviews58.2k followers
May 21, 2022
For some, suburban life is a family’s dream. Take, for instance, the Ellisons. Mona has a lovely home; her husband, Ben, a successful child psychologist; their son, Gus; and her book club buddies right across the street. It’s everything she dreamed of. But dreams can be shattered in the blink of an eye.

After an argument with his dad, Gus disappears and Mona spirals into a terrifying emotional state. The book club ladies do all they can to support their friend, but Mona pushes against that, harboring suspicions that something sinister is going on with at least one of them. Ben tries to help with counseling and medication, only to be met with more suspicion. Mona becomes increasingly obsessed with finding Gus. To start, she turns to social media. There she comes across a message from someone calling themselves ICU2. Could it be Gus? Excited, she follows clues from this post --- and, later, others --- to wherever the message leads her. Mona just wants to talk to Gus and see if she can persuade him to come home.

Meanwhile, once again, Ben has pressing business that takes him out of town. Concerned about leaving Mona in this fragile state of mind, he nonetheless hops on a plane. He assures her that it’s only for a couple of days. For Mona, though, a couple of days may be devastating. A couple of days is more than enough time for her to create wild conspiracies, see mysterious visions and hear creepy noises in the night. In Ben’s absence, she even glimpses Gus and tries to reach out. Her mind takes her all sorts of places and conjures up weird scenarios that ultimately lead her into a very dark space.

One day, as Mona is struggling to cope, the doorbell rings. She answers, only to find a policeman on her doorstep. He tells her that a young woman named Mia has been killed. Might Mona know anything about it? Naturally, she claims to have no idea who Mia is, but of course she does. She remembers Gus mentioning Mia. Now more than ever, she must find him.

The shocker comes when we discover what happened to Mia and where Gus has been all this time. And did Mona actually know the young woman, or did she dream it? Is part of this a result of all those medications she’s been taking? Speaking of the meds, where did they come from? Has Ben been trying to muddle her brain, manipulating her into thinking she’s going crazy? All good questions. And all questions that will be answered. Just not until you reach the end. Mona will explain it to you. But she also will tell you that she trusts no one --- including herself. So can you?

Susan Furlong’s WHAT THEY DON’T KNOW begins with a happy scene: a book club of four friends enjoying themselves. From there, the story takes a long, precipitous slide into darkness. Be prepared for a twisty ride. And pay attention because the reality seems to change from chapter to chapter. Don’t miss this highly entertaining read.

Reviewed by Kate Ayers
Profile Image for Debbie.
1,018 reviews11 followers
October 14, 2022
Oh, my, goodness. I picked this up to read last night and couldn’t put it down. I can tell you one thing, I was glad the lights were on and I wasn’t reading my Kindle in the dark.

This story grabbed me quickly with lots of questions, creepy dolls, and characters who had me snuggling deeper under the covers. Who were these people? Could any of them be trusted?

As I read a good book, a niggling voice is always whispering from the wings: Will the ending ruin the whole story? But as I read What They Don’t Know, for some reason I felt confident Susan Furlong wouldn’t let me down. And she didn’t.

I’m one of those odd people who don’t usually read a synopsis since I don’t want anything to ruin my discovery of a story as it unfolds, so as this story unfolded I was intrigued and continually making guesses. I couldn’t close the book. So I read on. And on. And on.

Mona Ellison, the protagonist, kept me going like a yo-yo. She had porcelain dolls that she seemed far too attached to. She acted completely paranoid, or was she? And then there is her bad-boy son who had disappeared. Not to mention her husband, who might be absolutely wonderful, or is he just acting the part? So I read on. And on. And on.

My Concerns
It was either due to the hour, I finally finished the book at 3 a.m., or there is some truth to my concern, I don’t know since my mind was probably a little fuzzy, but I felt the last third of the book was too repetitive.

Final Thoughts
The need-to-know will keep the pages turning. I feel sure this suspenseful book with a twist at the end won’t disappoint. It is a well-written story that you will want to allow lots of time to read.

Whose reality can be trusted in this small-town story of friends?

Since this is the first time I’ve read anything by this author, I’m definitely adding Furlong to my watch list.

My thanks to Seventh Street Books and the author for a gifted copy to review.
Profile Image for Mark.
Author 67 books173 followers
November 28, 2022
Mona Ellison's life is as perfect as the porcelain dolls lined up on her shelves. She has a successful husband, a loving son, a beautiful home, and a supportive group of girlfriends ever ready for their weekly wine night. But when Mona’s son gets entangled with the wrong crowd and runs away from home, her blissful suburban world begins to unravel. She tells her friends that boys will be boys, that he’ll be back as soon as his money runs dry - but deep down she knows there’s something else going on. And when the police show up at Mona’s door with news a young girl has turned up dead in their quiet town, it seems her missing son is the prime suspect.
This is the first standalone novel I’ve read of Sue’s and it won’t be the last. The characterisation is sharp and often painful - we get the story from Mona’s first person POV and also the lead detective on the case called Reyes - and it’s very atmospheric, making the most of a limited number of locations to maximum effect. But where the book shines is in its perfectly realised and unrelenting psychological suspense (or horror, if you like) - Mona is under the thrall of her psychologist husband but she’s clearly not herself because dead people can’t leave her messages, can they? As the tension increases and Mona’s world further unravels, the plot twists and turns, each one a surprise but perfectly in keeping with the piece. A cracking novel, I’d very much recommend it.
Profile Image for Joan.
4,379 reviews125 followers
May 13, 2022
This is quite an adventure into the mind of a crazy woman. We live in her head and we see reality through her eyes and interpret it through her mind. We become aware of events as she does. The narrative is written in such a way that we know there is a mystery but frequently we only know what Mona thinks about what's happening. Her obsession with dolls is creepy. It is also revealing as she describes herself in childhood as like a broken doll.

This is a good psychological thriller. We get immersed in the character of Mona like nothing I have read before. The plot is a tricky one that requires a great deal of detailed planning and execution and convincing. Now that I know the outcome, I wonder if it all works. The meds, for example. The end is a bit abrupt so we do not get a sufficient denouement, explaining how the details fit together in the end, how our perceptions of reality fit with reality itself. It leaves a haunting feeling after turning the last page.

This is a good novel for readers who like a psychological thriller. Be prepared to live in the mind of a mentally unwell woman.

I received a complimentary egalley of this book through Partners in Crime Book Tours. My comments are an independent and honest review.
332 reviews4 followers
October 7, 2022
I received a copy of this book as a Goodreads giveaway. "What They Don't Know" is a slow-building, multi-layered, and complex story set in Belington, Illinois, that has a great mixture of intrigue paranoia, dark pasts and suspenseful twists and turns to keep the reader engaged until the surprising conclusion. The main character, Mona Ellison, is living a dream life but one little comment on a current news bulletin, leads to catastrophic events.
As Mona spirals further from her once cozy reality, I felt, as a reader, that this small-town thriller was developing quite well until a final and shocking twist that rocked me to the core. Susan Furlong's writing style, based on using a narrator that you’re not sure whether can be trusted or not, definitely improves the suspense.
Profile Image for David Morgan.
932 reviews25 followers
May 20, 2022
A murder, a psychiatrist and a grieving mom with a twisted sense of reality.
Mona's not herself since her son up and left. Her husband, a doctor, is treating her for depression and anxiety by giving her a cocktail of meds. During a book club meeting with her closest girl friends and neighbors the subject of a girl found dead in a local lake is mentioned which gets Mona thinking. When the police come knocking, asking questions about the girl and where her husband is Mona's head spins and so will yours.
Mona is the definition of the unreliable narrator. Her character is so richly drawn it causes you to question her every thought and move. Her attachment to her collection of dolls is downright creepy. The writing is easy to get lost in. The twists and turns are numerous and the final one's a doozy.
If you're attracted to domestic, psychological suspense novels I highly recommend you pick this one up, I don't think you'll be disappointed.
.
Thank you to the author, Seventh Street Books and Saichek Publicity for the gifted copy for me to read, review and enjoy.
1,142 reviews14 followers
November 9, 2022
This book was so interesting. I finished it and thought about it a lot after putting it down. It's a suspense filled story of an unraveling woman, who lives with her narcissistic husband. In the end I wondered who really was crazy in the story. A good read.
Profile Image for Krista Hajjar-Nejad.
411 reviews19 followers
November 30, 2022
Ok, so this book threw me for a loop…but in a good way. Mona Ellison questions everything she thinks and does in this book. It made me question my own sanity at one point. I highly recommend this fast-paced psychological thriller. It’s packed with suspense, lots of twists, and conversations with creepy dolls. This was a crazy and wild ride. I read this book 24hrs. I couldn’t put it down until I knew who was behind all the madness. Can’t wait to read more from Susan Furlong!
Profile Image for Bill Mock.
377 reviews9 followers
May 20, 2022
I love it when I find an author who can switch gears so easily and effectively. I got hooked on Susan Furlong's work with the Bone Gap Travellers series, then stuck around for the cozy Peach series. But wow, this twisty tale of suburban drama blew me away.
Profile Image for Annie Kirchoff.
10 reviews1 follower
August 2, 2022
I loved how this book had me changing my prediction the entire time. And then I really loved the spooky ending.
Profile Image for Brooke.
1 review1 follower
August 19, 2022
Twists and turns around every corner and the ending leaves you frustrated and wanting more
Profile Image for Lauren Wieder.
16 reviews
March 16, 2024
This book pulled me right in. Susan's writing makes you feel like you are living the same nightmare or that maybe I am crazy. It keeps you guessing right up to the last sentence. This is my 2nd book by Susan Furlong and I will definitely be reading more!
Profile Image for Scott.
116 reviews
October 23, 2025
It’s not paranoia if they’re really after you. But are they?

Mona’s husband is a psychologist. He loves her deeply. (Does he?) And her friends? Only the best a woman could ask for. (Are they?) And her porcelain dolls are, well, a good respite from the stresses of life. But -

[Wait, excuse me? Yes. Yes, I said dolls. You got a problem with that? Take it up with Mona.]

- but despite the perception of happiness and privilege that one perhaps might see from the outside, a closer look might reveal a different reality. Mona is on medication that her husband compassionately monitors and prescribes to her. After all, he’s the doctor. And her son Gus has gotten in with the wrong crowd. He left the house one night after a heated argument and he hasn’t come back. She’s sure he will. He’s got to, right?

Then the police come knocking. A girl has been found dead, and Gus has inexplicably shot to the top of the list of suspects. But Mona knows he’s innocent. He’s got to be, right?

But where is he? How can Mona prove Gus is innocent when she doesn’t even know where he is? And if he’s innocent, who did kill the girl?

Is it someone she knows? Someone she loves? Is she next? Is Gus in danger? And where IS Gus?

In this psychological thriller, a cozy life in the suburbs is turned upside down. Friendship puts up a For Sale sign and Distrust moves in to host the weekend barbecue. Familiarity fosters jealousy, obsession, depression, despair, and rage.

Who can Mona trust? Who do you trust? What if nothing is as it seems? Or maybe the scarier question: what if it is?

This book was extremely good. I couldn’t wait to sneak a page in whenever I had a spare minute. It was like an addiction, with each chapter beckoning me to read just one more at the end of each day. And then one more. Often murder mysteries keep you guessing, but this one took it to a new level. I was just a bystander, observing through words the lives of some make-believe people, but I found myself constantly changing my opinion of each character - right until the very last sentence.

This was the first book I read by Susan Furlong (and, just for the record, though it has no bearing on the story, also the first one I’ve read electronically) but the whirlwind of psychological twists and surreally creepy suspense that kept me reading - and guessing - guaranteed it will certainly not be my last.

Thank you to Lola’s Blog Tours for an advance copy of the book in exchange for an honest review.
Displaying 1 - 30 of 93 reviews

Can't find what you're looking for?

Get help and learn more about the design.