The Stone Family struggles to unlock their mysterious wave of frightening 828 callings, while the person who may be key to solving them is trapped behind bars. Meanwhile, a shocking and disturbing incident leads Grace to suspect a local mom is in danger.

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.

In the wake of a devastating tragedy, Ben tries to connect with a despondent Olive. Michaela questions Jared's loyalties, and Saanvi shares a medical breakthrough that could change the course of all their lives.

When Grace's pregnancy complicates the pursuit of a calling, Ben finds himself working alongside an uneasy new ally. Michaela tries to make amends with Jared, and the X'ers set their sights on Zeke.

As the passengers adjust to a frustrating new reality, Ben and Michaela seize an opportunity to solve a Calling, with the Registry in hot pursuit.