A gripping dystopian science fiction novel by James Dashner and the fifth published book (second prequel) in the The Maze Runner series. It bridges the gap between The Kill Order and The Maze Runner, revealing the origins of the Maze experiments and the truth behind Thomas's past.

The novel follows Thomas, one of the few children who is naturally immune to the deadly Flare virus. Raised inside the headquarters of the organization known as WICKED, Thomas grows up alongside other immune children, including Teresa, Newt, Minho, and several future Gladers.

As WICKED's scientists develop the massive Maze Trials, Thomas begins to question whether the organization's ruthless experiments can truly save humanity. Despite believing that "WICKED is good," he witnesses increasingly cruel decisions and painful sacrifices made in the name of finding a cure. Torn between loyalty and conscience, Thomas must decide where he stands as the Maze project nears completion.

The novel culminates in the events immediately preceding the opening of The Maze Runner, explaining how the Gladers lost their memories and were placed inside the Maze. It also answers many long-standing questions about WICKED, Teresa, and Thomas's relationship with the organization.