Bishop arrives in uniform at her "home" where she is working undercover as McGee's "wife". Their home is directly across the street from a couple who are suspected murderers.
A week earlier, while back at the bullpen, Bishop reveals to McGee that Tony and Zoe are going through a rough patch. McGee is miffed because Tony told Bishop but not him.
Gibbs informs Tony they are going to Quantico to see Major Sussex Newton because he asked to see them, ostensibly about case that had been closed a couple of years ago, involving the theft of munitions. The culprit was caught, tried and convicted, but Newton always believed there was an accomplice. Ever since the case closed, he's been working on the accomplice theory on his own time.
Tony and Gibbs arrive for the meeting, only to discover that Newton has been killed while jogging.
In checking Newton's room, Tony discovers a used plastic knife that was placed in a napkin which was then placed in an envelope.
Abby discovers, through Newton's fitness bracelet that his heart stopped at one location, and his body was moved further away. Ducky also tells Gibbs that the injury on Newton's forehead was done post-mortem, and that Newton was killed.
Abby tells Gibbs she found a fingerprint on the plastic knife that was in Newton's room, belonging to Lauren Hudson, the civilian wife of Captain Dean Hudson.
Tony and Gibbs interview the Hudsons. They don't learn anything though they suspect the couple knows something about Newton's death.
The Hudsons claim to have not realized that Newton was at Quantico. Bishop and McGee prove they were lying, when they discover that Dean Hudson's credit card was used at the base restaurant the day of Newton's murder. The restaurant security footage shows Dean shaking hands with Newton.
Gibbs assigns McGee and Bishop to work undercover as a married couple so they can get to know the Hudsons and investigate them more closely.
McGee answers Bishop's phone when Jake calls, and inadvertently ruins the surprise anniversary trip Bishop had planned with him.
McGee tries to apologize but Bishop can't cheer up. She reveals to him that she and Jake are having problems.
Abby discovers that Lauren Hudson isn't who she says she is. She's impersonating the real Lauren. The real Lauren had inherited her father's estate. The NCIS team theorize that she was killed so that the fake Lauren and Dean could take her money.
Bishop notices that Dean has left the house, so she tells Abby she's going into their house to do some investigating.
Bishop breaks into the Hudsons' house. She discovers a prescription bottle belonging to Rita Applegate, the true identity of the woman impersonating Lauren Hudson.
McGee meets up with the fake Lauren at a coffee spot. One of the military staff blows McGee's cover by asking him a question about Newton's murder. He identifies McGee as an NCIS agent. The fake Lauren flees while phoning her husband to tell him about him.
She gets in her car, and McGee catches up and points his gun at her, telling her to put her hands on the steering wheel.
Dean Hudson arrives home, and Abby phones Bishop to try and warn her. Bishop doesn't pick up, so Abby phones Gibbs to tell him to hurry to the house.
Bishop opens one of the boxes and discovers the real Lauren's body parts. Dean tries to kill her but she manages to stab him with a pair of scissors. Gibbs and Tony arrive to arrest him.