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.
The adventure unfolds as Tom Sawyer and Huck Finn – Tom’s friend from the streets – witness a murder in the graveyard. Tom and Huck flee to Jackson Island and make a pact never to tell anyone about the incident. However, when the good-natured Muff Potter, who has been blamed for the murder is sentenced to death by hanging, Tom breaks his promise and returns to exonerate Muff Potter. In jun Joe, the actual murderer, makes a hasty exit from the courtroom during the trial. A short time later, Tom and Huck find references to a treasure and have to face In jun Joe again.
Skylar finds out that her parents are monster hunters after she accidentally releases some monsters from a secret containment chamber; so she and her techno friends must recapture all the monsters and also save her mom and dad from these monsters who are out for revenge.