The Bunker Diary by Kevin Brooks
Runaway teen Linus Weems has been drugged and left in an underground bunker with no food and no explanation. Soon, other people start arriving via a mysterious elevator and we get to see how this diverse group of people act under trying circumstances.
This book reads like a psychological study done without the intervention of an ethics board. Very disturbing things happen—if you’re not up for peering into the dark side of humanity, steer clear. However, if you are a fan of books like House of Stairs and Nothing, I recommend giving this one a try.