A teenage boy wakes up with no memory of his identity in a community of other young males, all trapped at the center of an enormous and deadly maze. The only thing he can remember is his name, Thomas. He learns that this group, known as "Gladers," has been trying for two years to find a way to escape through the maze that surrounds their living space, which they call the Glade. Every month, a new boy arrives with supplies in the same elevator Thomas came from. The Gladers have developed a society with roles, and the most daring are designated as "Runners" tasked with exploring the maze in attempt to map it and look for an exit. Each night, the maze shifts its configuration, and the monstrous "Grievers" that roam the maze make it lethal to be caught outside the Glade after dark.

Despite the established order, Thomas's arrival brings unprecedented change. He exhibits a strong curiosity and a remarkable ability to think on his feet, which makes him stand out among the Gladers. As Thomas starts to reclaim shards of his memory and spends time with the Runners, he becomes determined to lead his new friends out of the maze. Complications arise with the appearance of the first girl in the Glade. She recognizes Thomas and delivers a cryptic message that implies a connection to him and the maze, hinting that everything the Gladers think they know about their predicament is about to change.