Upgrade is the new mind-bending thriller from Blake Crouch, author of the bestselling Dark Matter and Recursion.

"You are the next step in human evolution..."

At first, Logan Ramsay isn't sure if anything's different. He just feels a little sharper. Better able to concentrate. Better at multitasking. Reading a bit faster, memorizing better, needing less sleep. But before long, he can't deny it: something's happening to his brain. To his body. He's starting to see the world, and those around him, even those he loves most, in whole new ways.

The truth is, Logan's genome has been hacked. And there's a reason he's been targeted for this upgrade. A reason that goes back decades to the darkest part of his past, and a horrific family legacy. Worse still, what's happening to him is just the first step in a much larger plan, one to inflict the same changes on humanity at large, and at a terrifying cost. Because of what Logan's becoming, he's the one person in the world capable of stopping what's been set in motion.

But to have a chance at winning this war, he'll have to become something other than himself. And even as he's fighting, he can't help wondering: what if humanity's only hope for a future really does lie in engineering our own evolution.