An NCIS case changes from accidental death to murder when evidence reveals that a Navy lieutenant died of forced over-hydration. Meanwhile, Gibbs meets Ducky's new love interest.
The NCIS team investigates the murder of a former Navy intelligence officer who had been living a double life and traveling overseas on false passports.
Billy and Mimi find the game is up after Micky finds them in a compromising position. Billy is scared as the Maguire brothers want his blood for daring to marry their mother. Kelly's not sure about keeping the baby and Jamie ends up finding out more than he bargained for after he confronts her at work. Kelly realises she has to be honest with him but will he still want her and the baby. Carl sees a crime being committed but walks past, unaware of the consequences. Billy's stag ends up being a night to remember.
The teams merge into one and learn that they have a chance to avoid an elimination if they're able to collectively lose 100 lbs. during the week. A candy-temptation setup complicates their efforts, however. Also: The players navigate a haunted maze and collect apples during a Halloween-themed challenge