Hetty has left NCIS and Callen and the team press Director Vance and interim Operations Manager Lauren Hunter for information on Hetty's whereabouts. We see Hetty in a European city at night; she enters a house and tells two men sitting at the table that she has a message to deliver to Comescu. The men attack and Hetty shoots them both dead. At headquarters, Callen decides the team needs to do their own investigating to make sure Hetty is safe and they head to her house. There they find three mercenaries ransacking the place, a gunfight ensues and our team kill all three men but don't find Hetty anywhere. Eric and Nell identify the mercenaries which leads them to the leader. Callen and Sam work him in the interrogation room and he reveals the man that hired him to ransack Hetty's house and find a memory stick with an important file, the man's name is - Comescu. Callen continues to press Vance and Hunter for info on Comescu and Hetty. Vance finally reveals that Comescu is a Romanian mob family that is after Callen and that is why Hetty left NCIS -- to protect him. Nell, after cross-referencing Hetty's alias with flight records, finds she is in Prague. Callen wants to go to Prague in order to save Hetty from this suicide mission but Vance refuses to let him go. Callen slams his badge on the table and resigns. Sam, Kensi and Deeks follow. The team goes rogue and heads to Prague but Callen will soon discover the mission is much more than a mafia family feud and he is about to find out many secrets that he may not be prepared for from his past.