Every once in a while, a book comes along that feels like it was crafted to tug at both your heart and your imagination. For me, The Book of Lost Hours was one of those rare reads. It’s part historical fiction, part speculative fantasy, and entirely unforgettable.

At its heart, this is a story about memory—how fragile it is, how easily it can be reshaped or erased, and how desperately we cling to it when it’s all that’s left. I found myself thinking about my own memories, the little ones that feel ordinary but actually make me who I am, I realized more than once as I read. The novel doesn’t just tell a story; it challenges you to think about what it means to remember and what it means to lose.

I loved how Gelfuso built the Time Space, a magical library of sorts where memories live on in books. The imagery was gorgeous, sometimes haunting, and I could almost see the shelves stretching into infinity. There were pages where I slowed down just to soak in the language—it felt like the story was inviting me to linger.

The characters are another reason this book hit me so hard. Lisavet’s resilience, Ernest’s conflicted heart, Amelia’s search for truth—each of them brought something unique and human to a story that could have easily been swallowed by its own big ideas. Instead, they made it intimate. I cared about what happened to them as if they were people I knew.

By the time I finished, I felt that bittersweet mix of satisfaction and sadness you only get with great books: happy to have experienced it, reluctant to let it go.

The Book of Lost Hours isn’t just a story about lost time—it’s about the weight of memory, the cost of truth, and the love that persists even when history tries to erase it. It reminded me why I love to read—because sometimes a book doesn’t just entertain you, it changes how you see the world.

4.5 ⭐️⭐️⭐️⭐️💫

THE BOOK OF LOST HOURS by Hayley Gelfuso was such an imaginative and captivating read. Can’t believe this was her debut novel — it was so creative and beautifully written. Think Kristin Hannah meets magical realism.

The worldbuilding of the “time space” was haunting and unique, and I fell in love with these characters. I truly felt their emotions, and even got a little choked up toward the end. Lisavet’s journey especially broke and healed me all at once.

The twists had my jaw on the floor — and after that ending, my head is still spinning. I’m honestly questioning if maybe I’m in the time space because… what the heck just happened?!

The pacing slowed a bit in places, but overall this was emotional, imaginative, and unforgettable. A story that will stay with me long after I closed the book.

✨ Perfect for fans of historical fiction with a touch of magic and a finale that will leave you reeling.

(Even though this book is already out, I received it from NetGalley as an ARC and I’m so incredibly grateful for the opportunity to start reading it before it was released!)

The Book of Lost Hours is a unique dual timeline novel. Time is pretty fluid for both Lisavet and Amelia, due to their connection to the time space. The time space contains all the memories from all of time. Lisavet is thrust in to the time space as a child in 1938 by her father in order to protect her. Amelia only learns about the time space when at 16, the uncle who raised her has died and a mysterious woman asks her for her help.

Several agencies across the world have equipped their agents with watches used to enter the time space and have been entering it to destroy those memories they think are a threat to them. This adds politics and international intrigue to the story of these two women who didn’t choose this world but are essential to it.

I enjoyed the novelty of the time space and the way that the two women are woven in and around it. The story was too long for me and seemed to drag in spots. It may have tried to incorporate too many plot lines and time lines.

If you enjoyed the Ministry of Time or the inner workings of international politics, you will want to pick this one up.

Thank you NetGalley and Atria Books for the ARC.

Once again another book that makes me curse the lack of half stars when rating because while it wasn't quite 5 stars for me I also feel like 4 stars doesn't do it justice. I could see where if this is genre / time frame is something you love then the book could easily be a 5 star read for you.

The Book of Lost Hours is outside of the norm when it comes to books I gravitate towards but the blurb was so intriguing I knew I needed to read it. I was not disappointed; the storytelling, character development, twists and turns in the plot - all amazing. If this is the authors debut novel I can't wait to see where she goes.

I love a good historical fantasy. Add in a sci-fi element related to time travel and you've got my attention. This book was so beautifully written - the plot was designed to weave inside itself and connect the many different themes and character. I loved it so well. It tugged at my heart strings, it was relatable, and it was exciting. I will be thinking about this one for a long time.

The Book of Lost Hours is an ambitious and beautifully imagined debut that blends historical fiction, fantasy, and suspense. Hayley Gelfuso introduces readers to the mysterious “time space,” a haunting realm where memories of the dead are preserved, and through dual timelines—1938 Germany and 1965 Boston—she explores themes of memory, loss, and the danger of forgetting. Lisavet’s journey in particular is moving and unforgettable, her strength and grief giving the story its emotional weight.

While the pacing shifts at times and some side characters are less developed, the central concept and atmosphere are captivating. Gelfuso’s writing invites readers to consider who controls history, what it means to remember, and the cost of forgetting. A thought-provoking and powerful read, perfect for fans of historical fantasy with a literary edge.

⭐️⭐️⭐️⭐️ (4/5)

All I can say is, Hayley Gelfuso, how can this be your first novel?

The Book of Lost Hours follows Lisavet Levy and Amelia Duquesne that are intertwined in a way that readers will never expect. The plot twists and romance came out of nowhere for me, and I absolutely loved the relationships in this novel, both romantic and platonic. Gelfuso also does a lovely job on spinning the topic time travel into something fresh and exciting, keeping me on my toes throughout my journey. All in all, I very much enjoyed this book, and highly recommend everyone to read it...so you can sob like me.

By the end of this novel, forget-me-nots have become my favorite flower, and the moon shines just a bit brighter than before.

I LOVED reading The Book of Lost Hours. Among a large (...very large, still growing) subgenre of "books about books and book magic," this stood out.
The plot twists were well-crafted and landed with me. I enjoyed the characterization of two very different teenage girls as main characters. I also appreciated the range in years this was set.

I will absolutely pick up Hayley Gelfuso's next book!

This was so good that as soon as I finished, I had to immediately tell a coworker to read it. There were a couple of times I was tryiing to keep track of what year we were in but the plot was intriguing. There were some quotes and scenes that I wanted to look around at the world we are in and go same feeling now.

Thank you to NetGalley and Atria for the ARC in exchange for an honest review

I would recommend if you're looking for (SPOILERS)

-m/f historical speculative romance
-dual timelines
-forbidden romance
-amnesia
-its always been you
-time travel

This was a gorgeously written book. The history brimming on every page, the aching loss, the intrigue. It sucked me right in and I had to know how it ended. A beautiful story about sacrificing for the people we love, who is writing our history, and of love. A book I'm jealous of anyone who can read for the first time.

The Book of Lost Hours by Hayley Gelfuso

I was honored to have a chance to read an ARC of the author’s debut novel. This book explores time, memories, and the things we do to protect those we love the most. I enjoyed the language, imagery and character development in this story that spanned across two generations of timekeepers. This was a speculative novel filled with mystery and magic. While I enjoyed the story immensely, at times it moved slowly for me, perhaps because of the long chapters. Still this is a promising first start for the author showing her creativity and craft, and I look forward to reading more from her.

While most of the “twists” in the story were all very predictable to me, the story had me pulled in and wanting a happy ending for these characters. I was very satisfied with the ending.

This book is definitely named correctly because I lost so many hours attempting to read it. The Midnight Library is one of my favorite books so when I saw this was compared to that, I jumped at the opportunity to meet it. This compares to that in the same way a banana compares to a carrot. They are both produce, but that’s all they have in common. The only thing this has in common with The Midnight Library is that both protagonists are stuck in an otherworldly, magical library.
I loved the concept of this but it was so drawn out and so many times it felt like it could have ended, but then it kept on going. The writing style just didn’t do enough to keep me engaged.
I did like the twist in middle, which renewed my enthusiasm for this (but not for long) and I enjoyed the ending (not because it was the end, but because of how it ended).
Thank you to NetGalley and Atria Books for an advanced copy. I’m sorry I didn’t get to it sooner. The Book of Lost Hours hit the shelves on August 26th.

This book was so good!! This isn’t my usual type of book, and I can sometimes struggle with a fantasy book and find it hard to follow. That was not the case at all here - the plot was so interesting and so engaging, the characters were well flushed out and interesting, and I really enjoyed every minute of this!

I listened to the audiobook, and the different characters were all portrayed really well.

I also loved the ending - everything came together perfectly!

I really enjoyed this story. it was so intriguing and kept me hooked as the different timelines unfolded. The writing pulled me in, and I kept imagining the whole thing playing out on the big screen. Honestly, it gave me strong Loki vibes with its time-bending twists and tension. I need to see this story adapted into a movie or show because it was just that visual, rich, and engaging.

This is a really good book, for those who like some time travel with a little history thrown in, and some relevance to our current times. It has lots of twists and turns, and even when I figured some out in advance, it was still surprising. The daughter of a Jewish watchmaker finds herself trapped in the time space, a library of memories, when her family is killed on Kristellnacht. She sees representatives from different countries coming in to destroy memories and change history, and she makes it her mission to preserve the memories. It seems like the Nazi's are the bad guys, but as the books go on, we question whether the Americans' motives are that much better. The book goes back and forth in time, and was well written and entertaining.

I really enjoyed this book! While I know the twist was supposed to be Lisavet/Moira but it wasn't really a surprise at all. I suspected from the beginning. That is not to say that effected my opinion of the book. I thought it was unique and keep me interested in the story. I liked imagining what everything looked like, the time space and the memories. Would reccomend!

Thank you to the publisher for a netgalley.

Well, I loved this one. I love a good travel through time. However, this one is not your typical time traveling. And though I thought this was going to be more of a historical fiction book, I am happy it was not.

I loved where this story went. Lisavet's development in the story was so, so good. Her life, at times difficult and sad, was a story worth reading. Each character in the story had their part and played it well. Each layer that unfolded was so well done, and nothing left me feeling like there were plot holes.

I love Ministry of Time, which this one is compared to. And while I think there are some big differences, I loved them both!

Thank you first and foremost NetGalley for allowing me to read this book in advance and exchange for an honest review. The review is linked below. Thank you again.

Thanks to NetGalley and Atria Books for this free copy of "The Book of Lost Hours."

This stunning debut novel is without a doubt one of the best books I've ever read! Finishing this book left a quiet little "forget-me-not" in my heart that keeps tingling.

I adore time travel novels woven with enduring love stories and author Gelfuso created such endearing, memorable characters that I didn't want the book to end.

With timely themes of who "owns" history and how it's told and what we'd do to protect those we love, author Gelfuso blends them into the narrative without being "preachy."

I absolutely can't wait to read what author Gelfuso writes next!