Clever, complex and compelling. Official Rating ~ 4.5 stars The audio really allowed me to get fully immersed into this unique novel. With each character having their own narrator it really brought their side of the story to life and gave them their own distinct personalities. I especially enjoyed Ben’s as throughout you can feel his melancholy and the toll this career defining case took on him. I enjoyed how you are fed the information and the clever timing of when it switches perspective and format. I, like everyone, was trying to piece it all together so I could answer the question we start this story with; Is she innocent or guilty? I quickly had my suspicions, which were correct but I never once saw the twists that came. I also like the fact that it’s written in such a way it gave the illusion that it itself is a REAL true crime story, one you’d easily find articles about either online or in the newspapers. Absolutely brilliant. And of course I loved that I was right not to trust a certain character. It made me feel smart! lol There was an aspect about the ending that I didn’t like but can’t explain without spoilers.

This is an incredible book written by an amazingly skilled author! The saying about assuming things is very true with this story, I believed I had everything figured out and the way it was written allowed that and kept me believing totally that my initial guess about X was right and then came those twists. Such a masterful wordsmith as this has written a book where the story is engaging, the characters become almost real people and ones you believe you have figured out. Then the author explains the truth of what you have been reading and even though nothing is how you thought it was, it makes sense and everything is understandable. This was a fascinating look into sleep disorders and the legal system, I'm so glad neither I nor my husband sleep walk! IYKYK

Anna O has been continuously asleep for the last four years after being found next to the dead bodies of her friends. Forensic psychologist Ben is an expert in the field of sleep and is tasked with waking Anna in the hope of uncovering the truth about what really happened. I loved this incredible fast-paced thriller. This book inspired so much curiosity in me that I couldn't put it down. I felt like I had to get to the end as quickly as possible because I needed to know the truth. I found myself wanting to know more about sleep conditions as the whole concept was really intriguing. I was constantly covering up the page to stop myself reading ahead of where I should be – out of pure impatience to get to the next part! I particularly enjoyed how the story was told from different character perspectives as it worked so well for the plot. The perfect book if you love a unique idea. Thank you HarperCollins for sending this book for review consideration. All opinions are my own.

Anna O is an amazing thriller, beautifully and cleverly written, gripping, fast-paced and is full of twists and suspense that will leave you shocked! The spooky and tense atmosphere that comes across in this story sent chills down my spine whilst reading, I just could not put it down. It has a plot that just keeps giving whilst also keeping you guessing. A fabulous psychological thriller and definitely a must-read of the year. I absolutely loved it and cannot wait to read more from this author.

Huge thanks to the publisher for this ARC, this was a really compelling read. It’s dark, mysterious, keeps you on edge. A great book.