A young boy awakens inside a dilapidated elevator with no recollection of his past or identity. He is soon welcomed by a group of boys in a large grassy area known as The Glade, which is enclosed by towering stone walls. Outside these barriers lies an extensive Maze that poses numerous challenges and dangers. Every month, a new boy and essential supplies arrive via the same elevator.
The established leader of the group is Alby, played by Aml Ameen, who reassures the new arrival that he will soon recall his name. Another key member, Newt (played by Thomas Brodie-Sangster), elaborates that the only possible escape from the Glade is through the perilous Maze. A select group of boys, dubbed Runners, venture into the Maze each day, seeking a pathway to freedom. However, they must return before nightfall; when the entrance shuts, the Maze transforms, becoming increasingly treacherous. The grave warning is clear: to stay overnight in the Maze is to invite death.
In a moment of rebellious curiosity, the boy attempts to escape the confines of the Glade by entering the Maze but is swiftly halted by Gally (portrayed by Will Poulter). Newt informs him that attempts to break free from the Maze have been ongoing for three years, but its ever-shifting nature complicates their efforts. In a moment of conflict with Gally, the boy suddenly remembers his name—Thomas, played by Dylan O'Brien.
Things take a dire turn when Thomas is attacked by Ben (Chris Sheffield), a Runner who has fallen victim to a Griever, a lethal techno-organic creature that roams the Maze at night. To protect the group, Ben is forced into the Maze and left to face his fate. Newt shares a piece of history about Alby, the first Glader, who spent a harrowing month alone in the Glade before meeting anyone else.
As events unfold, Minho, also a Runner, teams up with Alby to retrace Ben's steps into the Maze. However, calamity strikes when Alby is stung by a Griever. As dusk approaches, Minho manages to drag Alby back, but they can't reach safety before the entrance seals shut. In a moment of heroism, Thomas rushes into the Maze to assist them. Against all odds, he manages to eliminate a Griever by trapping it, and the trio survives the night. They return the next day, garnering disbelief and awe from the other boys.
Despite Thomas's bravery, Gally expresses his discontent, fearing that Thomas has disturbed the tenuous balance they have with the Grievers. Nevertheless, Newt promotes Thomas to the esteemed role of Runner. Joined by Minho and a handful of others, they venture into the Maze again, where they discover a beeping mechanical device inside the Griever's remains. This device seems linked to a specific Maze sector, hinting at possible escape routes.
In a surprising turn of events, a girl named Teresa (Kaya Scodelario) arrives in the elevator the very next morning. Thomas recognizes her, though he can't recall their connection. The note with her arrival declares she will be the last person sent down. Teresa, bearing two mysterious syringes, uses one to aid Alby, who gradually recovers from his Griever injury and starts to regain fragmented memories. He mentions that Thomas was "their" favorite, which raises questions about Thomas's role in the Glade and the trials they have all faced.
Later, Teresa shares her dreams with Thomas—dreams that mirror his own—and they uncover the truth of their past. They remember being subjected to experiments under the water and hear a haunting phrase: “wicked is good.” Minho presents a meticulously crafted model of the Maze, having explored it entirely, while coming to the conclusion that escape seemed impossible. However, with the clues from the device, hope begins to emerge.
Yet, their hopes are dashed when, during the night, the Maze walls remain open and a swarm of Grievers invades, leading to chaos. Alby and others are captured, and Thomas, in desperation, stabs himself with a Griever stinger, which Teresa has the antidote for. As he regains clarity, he realizes that both he and Teresa were part of the organization responsible for the Maze, which was nothing but a test after childhood puzzles grew darker, leading to the disappearance of their peers.
In a dramatic confrontation, Gally grows increasingly unstable, insisting they must remain in the Maze, and he attempts to shoot Thomas. But in a twist of fate, Chuck, a brave Glader, sacrifices himself, taking the bullet meant for Thomas. Minho retaliates and incapacitates Gally. As armed men storm in to extract the group to a helicopter, chaos ensues, but Thomas decides to resist their control.
As they escape, the Maze reveals itself to be situated in a vast wasteland. All hope seems lost as the helicopter approaches what appears to be the remnants of a once-flourishing city now buried in sand. This journey unveils the grim reality: the scientists behind the experiment on the group, now presumed dead, are in fact very much alive and declare that the trials have only just begun. The survivors are, in a chilling twist, about to enter Phase Two.
