After escaping the maze and facing the life-and-death test of the doomsday zombies, the forest fighters led by Thomas (Dylan O'Brien) finally ushered in the final battle between good and evil. The rescue team led by Thomas, Newt (Thomas Sangster) and others spent three years planning to rescue the captured Mino, but unexpectedly discovered that Mino was not on the hijacked train. After investigation, it was learned that Mino was deeply trapped in the control of the WCKD organization. Thomas and Newt resolutely decided to get up and go to the last pure land of mankind known as the "Last City". They even used Theresa (Kaya Scodelario), who betrayed the forest fighters and joined the WCKD, to break into the WCKD and rescue Mino and others.