When Thomas wakes up trapped in a massive maze with a group of other boys, he has no memory of the outside world other than strange dreams about a mysterious organization known as W.C.K.D. Only by piecing together fragments of his past with clues he discovers in the maze can Thomas hope to uncover his true purpose and a way to escape.

In the epic finale to the saga, Thomas leads his group of escaped Gladers on their final and most dangerous mission yet. To save their friends, they must break into the legendary Last City, a WCKD-controlled labyrinth that may turn out to be the deadliest maze of all. Anyone who makes it out alive will get answers to the questions the Gladers have been asking since they first arrived in the maze.