Part Four: Beech's trust in Frankie begins to slip, and as he sends her out on a number of errands, he keeps an increasingly twitchy Stanton under lock-and-key. However, Stanton manages to make radio contact with an outsider and he alerts Peters and Belmarsh, who begin a search for the underground bunker where she is being held. In an effort to escape, Stanton breaks the lock and shatters any chances of Beech letting her go. As the team locate Stanton's hiding place, they are forced to use cutting equipment to get through the steel door into the bunker. However, Beech hides three propane gas canisters behind the door, and an explosion ensues, securing his safe escape from capture once again. (thetvdb.com)