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.

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.