A boy awakens in a rusty elevator, completely lacking any memory of his identity. When he emerges, he is welcomed by a group of boys living in a vast grassy area known as The Glade, encircled by towering stone walls. Beyond these confines lies an expansive maze. Every month, a new boy, along with necessary supplies, appears via the elevator. The leader of this group, Alby (Aml Ameen), informs the boy that his name will soon come back to him. Newt (Thomas Brodie-Sangster), Alby's second-in-command, elaborates that the only escape from The Glade is through the Maze. During daylight, designated Runners venture into the Maze searching for an exit, needing to return before nightfall when the entrance shuts tightly. The chilling truth is that no one has ever survived a night in the Maze.
Attempting to leave the Glade, the boy nearly enters the Maze but is intercepted by Gally (Will Poulter). Newt informs him that the inhabitants of the Glade have been seeking a way out for three years. Complicating matters, the Maze's configuration alters every night, hindering the Runners' attempts to locate a potential exit. The boy soon finds himself in a conflict with Gally and, in a flash of memory, recalls his name: Thomas (Dylan O'Brien).
Later on, a runner named Ben (Chris Sheffield) returns, having been stung by a Griever—an eerie techno-organic creature that roams the Maze at night. Due to the danger he poses with his infection, Ben is forced into the Maze by the other Gladers to prevent further harm. Newt recounts Alby's harrowing month alone after arriving in The Glade, before anyone else.
Minho, another Runner, partners with Alby to retrace Ben's footsteps in the Maze, but shortly after, Alby falls victim to a Griever sting. As dusk approaches, Minho drags Alby back, but time runs out, and they cannot reach safety before the entrance seals shut. Determined, Thomas bravely ventures into the Maze to assist them. Miraculously, all three manage to survive the night, with Thomas defeating a Griever by cleverly trapping it within the shifting stones of the Maze. They return the following day, baffling the other boys with their survival.
Despite Gally's discontent at the risk Thomas posed to their tentative peace, Newt officially promotes Thomas to a Runner. Thomas, Minho, and others delve deeper into the Maze, where they discover a beeping device inside the carcass of the deceased Griever. This device is linked to a section of the Maze, offering a glimmer of hope. But the next day, a girl named Teresa (Kaya Scodelario) appears in the elevator. Strangely, she recognizes Thomas, though he does not remember her. A note accompanies her stating that she is the last to be sent. Teresa brings with her two syringes filled with an unknown substance—one of which is used on Alby, allowing him to slowly recover from his Griever sting and regain fragmented memories. He tells Thomas he remembers him, stating he was "their" favorite and questions why Thomas was sent to the Glade.
Teresa shares dreams with Thomas that align eerily, revealing that they are not mere figments of imagination but memories of an underwater procedure they both experienced, which included a woman stating, > "wicked is good." Minho shows Thomas a meticulously crafted model of the Maze, asserting he has explored every inch with no escape found, yet with the mechanical device they retrieved, there might be hope. They delve back into the Maze—an experience both exhilarating and perilous that barely leads them back in time.
One fateful night, the walls of The Glade remain open, unleashing a torrent of Grievers. Chaos ensues as Alby and others are attacked. The remaining Grievers retreat, taking Alby with them. In desperation, Thomas inflicts a wound upon himself with a severed stinger and, upon being cured by one of Teresa's syringes, remembers their involvement in the organization that orchestrated the Maze, realizing it was part of a larger experiment. This test had begun during their childhood, with puzzles set to gauge their abilities, and then came the disappearance of the elder boys, starting with Alby—the turning point marking their entry into the Maze. Gally's violent intentions are thwarted by the Gladers who choose to rally with Thomas, journeying toward freedom through the maze's escape route.
Their trek leads them to a facility filled with lifeless scientists. Here, they uncover an unsettling video of Eva Page from WCKD (World Catastrophe Kill Zone Department), explaining the devastation wrought upon the Earth by solar catastrophes, succeeded by a global pandemic targeting the brain. The Gladers were subjects in a study purposed to investigate the resistance of their generation to the virus and what set their brains apart from regular humans. The video culminates in Eva taking her own life as armed gunmen invade the facility.
Suddenly, Gally reappears, weapon in hand, lost to madness from a Griever sting. He lunges to stop them from escaping, shooting at Thomas. In a noble act, Chuck sacrifices himself to save Thomas, leaping in front of the bullet, while Minho neutralizes Gally with a spear. The Gladers are rushed by masked men to a helicopter, but Thomas, unwilling to comply, fights back.
As they soar over the Maze, the expansive desert landscape unfolds below, culminating in the haunting ruins of a city swallowed by sand. To the surprise of the survivors, the once-dead scientists are revealed to be alive, declaring the experiment a success as the group gears up to enter Phase Two of their harrowing ordeal.
