Review: The Kill Order is the fourth book of the Maze Runner series by James Dashner, and the events inside take place thirteen years before the beginning of Book 1.
It follows a group of people have that are trying to survive in a world ravaged by solar flares, tsunamis and whatnot which turned the everything we know in an unfavorable place at the expense of millions of lives. In this group are Mark and Trina, childhood neighbors and friends(also lovers), seasoned ex-soldiers Alec and Lana (convenient!), and other stray teenagers Darnell, the Toad, and Misty. They are living in a settlement out in the woods with other people.