When Cal wakes with a life-threatening fever, Grace worries it's a side-effect of his experimental cancer treatment, but Michaela and Ben suspect Cal's condition may be related to a mysterious passenger from Flight 828. As Cal's situation worsens, Ben and Michaela attempt to track down the now-missing passenger.

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.

Ben forms an unlikely partnership with Vance in a high-stakes race to locate the missing passengers of Flight 828. Meanwhile, Michaela helps a suicidal passenger who believes he is the Angel of Death, and Cal goes back to school, navigating both his unwanted celebrity and his former friends, who are all now 16 years old.

When Ben and Michaela put everything on the line to save the other missing passengers, the mission goes horribly awry and not everyone makes it out alive. The devastating result pushes Ben and Grace to a traumatic brink, while pulling Michaela and Jared dangerously close together.

Michaela's mystifying, next-level calling launches her on a mission that brings her relationship with Jared to a head. Determined to protect his family, Ben explores an alternate meaning to Michaela's calling that leads him to a new alliance and a powerful new adversary. Cal's struggle with Ben's absence from home forces the Stones into an agonizing confrontation that could alter the family's fabric forever.

After finding another dead body, Michaela and Jared try to track down a serial killer. Cal goes on a date. Zeke faces old demons.

An ominous Calling shakes up Michaela and Zeke’s party. Cal and Ben receive devastating news. Michaela, Saanvi and Eagan look for the Omega Sapphire.

As the Death Date nears, Callings begin to take a toll on Cal. The group sends out a cry for help. A familiar face provides hope in an unexpected place.

The passengers race to solve their Callings as Saanvi tests a theory on the patients. Eagan makes a surprising move. Michaela confronts hard truths.

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.