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.

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.

When Grace and Cal are involved in a suspicious hit-and-run, Ben is determined to get to the bottom of it. Michaela investigates a brutal attack at the Church of the Believers, but finds her efforts stymied by Adrian's refusal to cooperate. Zeke is tested when he tries to make amends with someone from his past.

Ben and Saanvi work together to orchestrate a surprising family reunion for an emotionally closed-off Flight 828 passenger. Meanwhile, Olive drifts further away from her family, Jared learns more about a growing cabal of anti-828 sentiment, and Michaela finds herself out on a limb when baggage from Zeke's past threatens to destroy his tenuous new life.

Tensions flare as the passengers of Flight 828 finally come to understand the meaning of their increasingly terrifying callings. Afraid of losing his daughter to the Church of the Believers, Ben confronts Adrian. Zeke challenges Michaela's trust, and Saanvi seeks help from an old flame.