Thomas, Newt, and Frypan are the last of the free "Gladers" immune to the Flare virus that has ravaged the world's population. Against the orders of Vince, who now leads The Right Arm resistance, the three leave their camp to rescue their immune friend Minho, who is being tortured by the organization WCKD in hopes of developing a cure for the virus. Heading for the "Last City", where WCKD's headquarters is located, the group is attacked by Cranks, humans infected with the Flare. However, they are saved by Jorge and Brenda, who join them.