If you haven’t seen the first two installments of the Maze Runner sci-fi series, this third episode won’t make a lick of sense. It begins in medias res, its young-adult heroes and their grown-up allies carrying out a dangerous rescue operation in the desert; after that, the characters journey to places whose significance will be apparent only to the initiated. The story has something to do with evil scientists experimenting on imprisoned children in hope of finding a cure for a devastating plague. Director Wes Ball fails to generate any emotional resonance with this premise, though some of the action sequences are exciting. With Dylan O’Brien, Rosa Salazar, Aidan Gillen, and Patricia Clarkson.