In 1986, teacher Brian Keenan (Ian Hart) moves from his native Ireland to Beirut, where Hezbollah militants kidnap him. Brian is held captive with one other cellmate, British journalist John McCarthy (Linus Roache). John is calm by nature, while Brian has a rebellious streak, and the two hostages have opposing political views about their home countries. Still, over the course of their grueling four-year imprisonment, they manage to develop an unbreakable bond.