While Jonas and the team continue to try to rescue his daughter, Betsy Blane, from Syrian captors, Mack has the opportunity to carry out his revenge on Ryan for his affair with Tiffy.
Sam helps an Afghani elder and former friend search for his missing nephew.
During an investigation into a suicide bombing at the U.S. Marine base, a discovery is made about a new, chemically undetectable bomb material; Gabriel is unable to finish a task.