The Maze Runner

The Maze Runner is a 2009 young adult post-apocalyptic  novel written by American author James Dashner and the first book released in The Maze Runner series, although it is the third in narrative order.

Plot
Thomas wakes up in a metal elevator that brings him to a place called the Glade . He has no memory of who he is or how he got there. He gradually discovers that the Glade is run by two boys: Alby, the leader, and Newt , the second-in-charge, who both maintain order by enforcing simple but effective rules. The elevator box surfaces from under the ground every week supplying new food, tools, and sometimes weapons. Every month a new boy with no memory of anything but his first name, finds himself in that elevator box. The Glade is surrounded by a square of 4 mile-high walls made of concrete. Outside the walls is the Maze, a labyrinth of high concrete walls covered in ivy that changes every day. The Maze houses strange, lethal creatures known as Grievers. Grievers are described as amorphous monsters of metal and flesh. The Gladers are trying to stay alive as well as "solve" the Maze by running through it as fast as they can while tracking movements of the walls and trying to find an exit to escape.

One day after Thomas' arrival, a girl named Teresa is delivered through the elevator into the Glade with a note saying "She's the last one. Ever." It implies that there will be no more children sent into the Glade. The girl subsequently lapses into a coma. When Thomas comes to visit her, he recognizes her, but can't remember her name until he hears her voice telepathically in his mind telling him her name. Teresa wakes up and tells Thomas that they knew each other before they were sent into the Glade, and reveals that they could communicate telepathically.