Will, Frankie and Susan are joined by Will's new girlfriend as they head to Spain on a mission to retrieve a case of plutonium from the wrong hands.

The team heads to Europe to transport a dangerous prisoner for interrogation, and the prisoner is Will's former boss; Jai helps organize a Secret Santa gift exchange for an off-season Spy Christmas.

Will goes to a dark place as he and the rest of the team are tasked with hunting down the culprit behind an unsettling attack.

Ollerman attempts to force the team to commit a terrorist attack for The Trust using Ray’s life as leverage. Meanwhile, Jai helps Standish deal with a revelation about Tina, and Will and Frankie come to a realization about their relationship.