The Bunker Diary by Kevin Brooks is a book about a group of people who were dumped into a bunker by a man who kidnapped others. The first person to go in was our protagonist, Linus. He kept a diary for every day and its events. Eventually, more people came down and they tried to escape and not die.
This book has a lot of suspense and mystery. I like this book a lot because it shows what humans can become when deprived of freedom.