The Book of Lost Hours isn’t about time travel or murder. It’s a story of ‘what if’, of the beauty and heartache of our choices and their repercussions, of the power of love, and so much more.
As a debut novel, I am inspired and awestruck. This novel is beautiful, emotional, and continuously intriguing, and I will absolutey recommend it.

Wow. Just. Wow.

This book really threw me into a deep spiral after I finished it. So much to contemplate. So much to ponder. Absolutely loved the ending with Amelia being the only one to remember the bookshelves and the previous memories.

This was probably my favorite book of the year so far, and I'm not sure if another one will top this!

This book follows Lisavet, an eleven year old who becomes trapped in a pocket within space and time where memories are stored between pages of books kept in a vast and magical library. Throughout this story we are witnessing her journey as she navigates new challenges, timelines, and her efforts to preserve the memories of the world.

I read this digitally, and I listened to an ambient playlist on Youtube titled, “You’re Invited to a Time Traveler’s House,” and it was a perfect match for this book. The visuals and piano classical music really pulled me into the storyline and I ate the book up so much quicker this way. I stayed up for a few nights in a row to finish this book.

I loved the concept of time and memories being stored within books, and I especially enjoyed the way we discover the world alongside her, learning new aspects of the world as she also learns it herself.

I didn't find the magic system too difficult to understand. This is a magic system where the details are shared over time, not all at once. I love the it's linked with old vintage watches, hidden doorways, and whimsical visuals.

The writing is absolutely gorgeous. Hayley Gelfuso writes like she's writing poetry, with dreamy, lyrical sentences. I had more annotations and highlights than I usually have in the books that I read, and I can't wait to purchase a published copy and annotate it for my shelves.

The multiple storylines may be difficult to follow if you're not initially expecting it, but the chapters titles are a great help in knowing what timeline you are in. It took me about three chapters to get a feel for the format.

Thank you NetGalley, Atria Books, and the author for an advanced copy of this book!

The Book of Lost Hours is definitely one of my top reads of 2025. I love time travel romances (The Ministry of Time, The Time Traveler’s Wife), and Outlander is probably my all-time favorite. This one felt like a time travel romance mixed with Eternal Sunshine of the Spotless Mind and I was hooked from the start. I loved Lisavet and Ernest’s connection and how it carried the story through different timelines. I literally could not put this book down!

Thank you NetGalley and Atria Books for the ebook ARC!!

“A sweeping, unforgettable novel following two remarkable women moving between postwar and Cold War-era America and the mysterious time space, a library filled with books containing the memories of those who bore witness to history.”

As soon as I saw this book I knew I wanted to read it for two reasons. Number one, Atria books never let me down. Ever. And number 2 it reminded me a lot of the concepts behind “The Midnight Library” and “The Last Letter from Your Lover” both of which I immensely enjoyed.

I loved the feeling of this book and how it flowed and ebbed like a TV show or movie. I loved the dual POV and dual timelines, even though I feel like I occasionally got lost not knowing if I was in the past or the present.

The characters are great and they truly feel like they have their own personality and structure within the story. And like most other reviewers have said…UGH JACK. Nope. Just nope on him.

The book may start a little slow, but once you get into it, the pace really picks up and you can’t put it down.

A very special Thank You to NetGalley, Atria Books, and the author for an e-ARC in exchange for an honest review.

The Book of Lost Hours is a richly imaginative, emotionally resonant debut that blends historical fiction, speculative fantasy, romance, and moral reflection. Its inventive premise focusing on memory, history, and agency has garnered widespread appreciation from critics and readers alike, though some have noted areas for deeper world‑building or pacing refinement. If you're drawn to stories that explore the power and fragility of memory, and the sacrifices we make to preserve truth, this novel is likely to stay with you.

Thank you to the author and publisher for providing me with an ARC! The Book of Lost Hours follows young Lisavet Levy out of Nazi Germany and into the time space. While there she grows into a woman while fighting a battle between her own morals and protecting those she loves.

Loved
- The historical aspects of the story are so poignant and terrifyingly relevant to the world we live in today
- The concept of governments regulating what is remembered in the time space and destroying anything that doesn’t align with their ideology
- Ideas being impossible to kill once they start to spread
- The way the story unfolded across time as we saw more of what happened to Lisavet in the time space and Moira and Amelia in the 1960s
- The grief I felt in the beginning when Lisavet is mourning both the loss of her father and the loss of her father’s stories

Overall this is a phenomenal book. It strikes a balance between magical realism and historical fiction so well. I just wish Moira had not been so unlikeable, although I absolutely understand why Hayley Gelfuso took her character on that path. 4.5 ⭐️

Read this if you love...
✨ time travel
🔎 Cold War intrigue
💙 generational sagas

To save his daughter's life during Kristallnacht, a watchmaker hides her in the time space and promises to return. Lisavet Levy never sees her father again. She grows up in the time space among books containing memories of the dead and only an ancient specter for company. When government agents start entering the time sphere to burn memories, Lisavet saves the remnants in a secret book. A chance encounter with a kindhearted American spy sets her on a new course. In 1965, grieving 16-year-old Amelia is approached by a CIA operative seeking a mysterious book of memories.

I couldn't tell you the last time I read a science fiction novel. The Book of Lost Hours certainly lies outside my usual genres, but I'm happy to have read it. It blends time travel with historical fiction in a way that feels unique and approachable for those unfamiliar with science fiction.

Gelfuso paints a compelling portrait of the time sphere, a collective library of human memory against a starry backdrop. Her characters are crafted with equal artistry, bringing readers deep into their heads and personal struggles. I emphasized deeply with most and wanted to fight a handful (it's on sight, JACK!) While still not my favorite, the multiple points of view worked best for the narrative and made the final payoff even better.

While I guessed several twists, it didn't make them any less thrilling. That masterful ending wrecked me. I recommend bringing tissues and something to help lift your jaw off the floor.

Thank you to @atriabooks and NetGalley for this eARC in exchange for an honest review!

I think this book was very well-written, but it's just so similar to other books with the same basic premise. It's like when a TV show gets great reviews and viewer numbers, so studios automatically think everyone wants to see clones of it. The writing is good, the characters are well-developed, but there's really nothing different enough about the plot to distinguish it from others with similar storylines.

The Book of Lost Hours has been compared to many other books: The Midnight Library, The Invisible Life of Addie LaRue, The Ministry of Time, The Night Circus, etc. I loved all those books, so I was not surprised to love The Book of Lost Hours as well.

The books starts in 1938 with Lisavet Levy, a young German girl living with her father and brother, being hidden in time space on Kristallnacht. She proceeds to get stuck, befriend a ghost, learn several languages, save people's memories, and fall in love with an American spy. And that's only the beginning! We also follow Amelia, a teenager in 1965 Boston, who is mourning the death of her uncle when she meets a strange woman who turns her life upside down.

Beautiful historical fiction with mysterious movements through time scattered throughout. If you enjoyed the books referenced above, I highly recommend you pick up The Book of Lost Hours, being released August 26, 2025.

Thank you to NetGalley, Hayley Gelfuso, and Atria books for the ARC in exchange for an honest review.

The Book of Lost Hours
A beautifully imagined story that blends history, fantasy, and a touch of romance. Moving between the 1930s and 1960s, it follows two young women—one trapped in a mysterious library of memories, the other facing grief—whose lives unexpectedly connect. The themes are clear and timely: the power of memory, the danger of censorship, and the heartbreak of erased truth. With its vivid writing and unique premise, this is a thoughtful and resonant debut, gentle in pace but rich in impact.

A cinematic, genre-blending (spy thriller, speculative fiction, sci-fi, historical fiction, and romance) page-turner with a soft spot for poetry (not surprising given the author’s background) as it probes the question of who gets to decide what and how history is remembered and disseminated, as well as whether abject and obedience trumps truth. I also appreciate how, post-novel, Gelfuso dedicates her novel to those fighting censorship.

However, the writing can be quite dry at times, the “twists” are not hard to guess, and Gelfuso overuses the word “spat” to describe particularly heated outbursts and dialogue.

Trigger warnings: death of an infant, suicide, murder, SA/r4p3.

This book combines elements of historical fiction, fantasy, and mystery, creating a world that feels both unique and immersive. I loved the idea of the time space; a hidden library of memories that can only be accessed through watches that have been passed down for generations.

Following Lisavet's transformation from a child alone and without anyone to a courageous memory-keeper who stands up to government censorship was especially moving. Her quiet strength and determination bring out themes of memory, loss, and the enduring importance of truth.

Amelia's storyline, which is set in the 1960s, adds another timeline to the narrative. The author very skillfully links the two different eras. Which end up prompting the reader to wonder how is history recorded and who does the recording? The weaving between the two timelines is confusing at times, but nonetheless an addition to the depth of the story. Reading how the mystery unfolded is one aspect of the story that kept me completely hooked.

Overall, this book is a thoughtful meditation on legacy, personal agency, and the delicate boundary between what is real and what is remembered. I would highly recommend it to readers who appreciate speculative fiction that is both emotionally resonant and rich in historical detail.

Thank you @librofm @simon.audio @atriabooks #partner for the gifted copy of this book!
4.5/5

This book gave me all the vibes. If The Ten Thousand Doors of January, The Midnight Library, The Book of Doors, The Invisible Life of Addie LaRue, and a Blake Crouch novel all had a baby… the result would be The Book of Lost Hours. I know that’s a lot, but for real...this story gave me all the feels.

We’ve got time travel, mystery, magical realism, historical fiction, adventure, and romance all wrapped into one atmospheric, unforgettable read. I am obsessed with the concept of a magical, time-space library where memories are stored. It truly just felt so cozy but also dangerous. Especially when people start rewriting those memories and darker consequences begin to surface.

I won’t spoil anything, but the moment this memory library was introduced, it had me completely hooked and it never let go. The world-building is rich and atmospheric. Hayley’s writing was so descriptive and gorgeous I could envision every part! The plot takes you on a truly unique, mind-bending journey that stayed with me long after I finished the book.

It’s enchanting. It’s magical. It’s unlike anything I’ve read in a long time...yet it gave me hints of so many books I already love. If you’re looking for something unique that will let you get completely lost in time, this one’s for you.

This book was a mashup of all of my favorite things: history, fantasy/sci-fi, romance, intrigue, espionage, and escapism. Following the story of two young women in different points in time, The Book of Lost Hours grips the reader right away.

Literally thrust into the mysterious and confusing Time Space, Lisavet is saved from the horrors of Kristallnacht by her watchmaker father. He promises to follow close behind, but never comes. She’s not alone, not really. Whisps of memories float amongst the endless bookshelves of the Time Space where Lisavet is now trapped. But there are also men lurking through the shelves, burning the books that contain memories to subvert their goals. She can’t escape, but she can do her best to stop these memories from being destroyed.

We flash forward in time and across the globe to meet Amelia, as she mourns the loss of her guardian, Uncle Ernest, after his sudden demise. She is met by a woman asking about her uncle’s watch, and warns her not to wind it if she happens to find it among his possessions. Amelia already has the watch, and obviously winds it the first chance she gets (as any teenager would do, once they were told not to, obviously). Nothing happens, and she tries to walk back into her classroom, only to be transported through that doorway into the Time Space as well. How was her uncle involved in such a mysterious and dangerous plane of existence?

This book blends the fantastical with the real life struggles of those tasked with preserving (or altering) history and how it’s perceived by later generations. The story and message are thought provoking and captivating. The characters throughout the book are well developed and intriguing. While integrity and moral justice are the main ideas of the message, the underlying romantic love story is the vehicle that keeps the reader engaged with the characters. Don’t get too wrapped up in the paradoxes of time travel, but suspend belief and enjoy the ride.

3.75
I read this book blind, not knowing what to expect, and it kept me entertained and curious, but I think the other half of the book was being so long and boring but there were some interesting moments of course that kept me pushing through, this book is so different from what I usually read, it’s a historical-fantasy and it felt like I was watching a movie, the diversity of characters and point of views, the setting, and basically just the energy of this book is what makes me think that.
I would highly recommend to people who love something special and not repetitive, it gives the feeling of a cold night in fall, which is coming soon so this is your sign to add it to your TBR and read it.
Thank you NetGalley and the publisher for the ARC in exchange of a honest review.

There’s no denying the amount of care and creativity that went into The Book of Lost Hours. It’s a really ambitious and unique story—kind of like The Ministry of Time meets Addie LaRue—with a twisty, layered plot that’s unlike anything I’ve read recently. The concept is so cool, and I loved how it blends historical fiction with speculative elements in a way that feels fresh.

That said, I did find myself a little confused by how some of the mechanics worked, and that pulled me out of the story at times. Around 30%, the pacing started to drag for me, and I was tempted to skim. But even then, the mystery and worldbuilding were enough to keep me reading. I had to know how it ended.

The romance didn’t fully work for me—it felt more like a “right place, right time” kind of relationship than something deeply developed—but I know some readers might still enjoy that dynamic. What stood out more to me were the themes of censorship, control, and manipulation of truth. Those parts hit hard and added a lot of depth to the story.

Even if it wasn’t a perfect fit for me, I really admire what this book set out to do. It’s an original, bold take on WWII/Cold War fiction, and I can absolutely see why it’s getting so much love on Goodreads. If you're into thoughtful, time-bending stories with strong political undertones, it’s definitely worth picking up.

I loved this so much. I could not put this book down. It has one of the most unique premises I've ever read. A library filled with books holding the memories of people who witnessed history. Time travel, romance, suspense. I was on the edge of my seat the whole time. The story weaves itself between post WWII and the cold war. I loved all these characters and the emotions I felt reading this were next to none. I would take a bullet for Ernest. I was heartbroken again and again. I was giggling. I was crying. Ah, so good! On my way to buy a bouquet of forget-me-nots.

A memory library…such an interesting concept to build a novel on. Based on a theory that time and memory are not just single constructs but differ from person to person, the library holds the memories of everyone who has ever lived. The world-building was largely done in the reader’s imagination with the help of the characters who could access the library. This is a combination of science fiction, love story, murder mystery, and suspense that held my interest for the entire book. It was such a treat to read a novel with a bit of unique story to tell.

Thanks to NetGalley and Atria Books for the ARC to read and review.

"I'll take care of you. I won't let anything happen to you. I'll rewrite all of history if I have to."
This was so good. From the moment I read the first page I was hooked, right up until the end. It was a unique story, about a girl lost in time and the lengths people will go to for the ones they love.