While Gavin enlists the help of his grandfather to guide him to his missing wife, Eve and Levi navigate a horrifying new reality. In 1988, Josh and Riley discover they’re being followed by a suspicious man who reveals information about the mystery behind the sinkholes.

A ruthless enemy holds the Clearing captive, threatening to kill a beloved Survivor if their demands for an unexpected item aren't met. Gavin and Sam lead the rescue attempt, aided by an old friend whose return holds more questions than answers.

As Gavin and Sam search for a secret military base, they're surprised by an old colleague of Gavin's who just may hold the clues to finding Eve. When Ty and Sam try to figure out how to bring their friends home, Ty becomes sidetracked as he confronts his demons from his past.