Ben and Michaela investigate a shocking murder in fear that it's connected to Flight 828. Meanwhile, Ben struggles to accept the life Grace led in his absence, while Olive and Cal realize that being twins after five and a half years apart is harder than they thought.

With the detained passengers secretly moved and subjected to painful experimentation - and Cal's health directly linked to them - Ben takes advantage of an old friend to find out where the passengers were taken. Meanwhile, a mysterious new version of the calling pulls Michaela into a murder investigation that has deep personal ramifications for her.

Michaela is pushed into the midst of a high-stakes bank robbery perpetrated by a mystery assailant. As Ben and TJ piece together an arcane set of mythological clues, Adrian draws Olive further into the world of the Believers.

While in pursuit of criminals, Michaela is sidelined by devastating news. Ben teams up with a gifted 828er to aid a young teen. As Grace confronts ancient family wounds, Olive explores ancient mythology in hopes of helping all the passengers.