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.

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.

Ben is drawn to help absolve a passenger of his guilt, while Saanvi enlists help in protecting herself from the Major. Jared and Drea attempt to extract a confession from a trio of ruthless meth dealers who would do anything to exact revenge on Michaela.

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.

Ben reunites with a duplicitous foe. Michaela and Zeke's dinner party with Jared and his new girlfriend is halted by a calling that ignites the Stone siblings to save the life of one of their own. Olive's friendship with Levi blossoms but is tested.

The Stones are reunited with Olive, yet their happiness is quickly interrupted when Cal runs away. As Michaela struggles to help the passengers avoid a deadly threat, her relationship with Jared sours over mistrust.

While investigating a Calling, Michaela finds a mysterious stowaway. Ben clings tightly to his beliefs. Cal comes out of hiding to pursue a lead.

Michaela, Vance, Jared and Zeke's search for Ben at the compound leads to an explosive confrontation — and a divine miracle.

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.

All signs point to the end of the Earth, spurring the Stone family and the passengers to work together and decipher cryptic clues before time runs out.