Thomas, a teen just woke up inside a metal box in the glade he doesn't remember anything but his name, when he gets out of the box he is surrounded by a group of teens who tell him that he is in the maze.
Later that day a lady arrived the same way Thomas did, through a metal box, this was very weird for the people that had been in the maze for a while. It was the first girl to ever arrive.
During Thomas's training to become a runner the Maze is threatened by a group of monstrous creatures called the Grievers. Thomas makes the decision to be stung by one of the grievers and uses the poison as an attempt to remember the past.
The Gladers make the decison to attack the grievers, during the attack they find the coumputer that they can then use to shut the grievers off.
Only half of the gladiators survive the attack and find the secret slide that leads to the lab, there they find Gally who tries to stab and Thomas but instead acidently stabs chuck.
Once out of the maze Thomas finds out there was a plauge that is wiping out millions of people and young orphans are being sent to the maze to look for a cure.