If you don’t like books that make you think, then you can expect Recursion by Blake Crouch will make your brain hurt. He writes great sci-fi, which isn’t always my jam, but both of Crouch’s books I’ve read have been fantastic.
Helena sets out to create a device that will help Alzheimer patients save their memories. And she succeeds. But the device does so much more than she intended and in the wrong hands, the device creates a world that is self-destructing due to memories being tampered with. Think sci-fi Groundhog Day meets the Matrix. Imagine reliving the same lifetime over and over only to get to the same day to have all the other lifetimes flood back into your memory. And then horrific things taking place as you try to stop them.
But don’t think too hard while you’re reading because you will lose your mind trying to figure out if what’s happening makes sense or is even slightly plausible. It’s not real but it is slightly terrifying. Enjoy (haha)!