The previous episode of NCIS saw the team investigating the murder of Petty Officer Second Class Maya Kettering. After her body is discovered by a pizza guy, the team investigates only to discover they are receiving help from the Sherlock private investigative team headed by Walter Osorio.
In addition to Nick and Alex being exposed to the Sherlocks for the first time, the audience discovers they have a new probationary detective, Anthony DiNozzo Sr. At the bullpen, the team updates Gibbs on the case, telling him Maya’s husband, Michael, is in the interview room with Ellie.
Michael Kettering seems distraught over what happened to his wife and tells Ellie he doesn’t know who would want to hurt her. Since he was on a plane during the murder, he is not seen as a likely suspect. He tells Ellie that Maya had a confrontation with her department head while she was on the U.S.S. Tallahassee.
Down in autopsy, both Ducky and Jimmy share their findings with Gibbs. Maya was strangled and she had fibers on her back, which were embedded in an area where she appeared to have a rash.
When Tim and Nick go to the victim’s house, they see the crime scene seal is broken and an electrician from Voltrane, Taj, is inside. Sheriff Osorio had apparently let him in to get the alarm panel. He also tells Tim and Nick an emergency stash of cash in the freezer was gone.
Meanwhile on the U.S.S. Tallahassee, Ellie and Gibbs are less than thrilled to see Judith, Lyle and Senior from the Sherlocks are there. Osorio had apparently made them honorary detectives.
After spotting Nick watching her work, Abby informs him the rash on Maya’s back was actually rug burn and the fibers embedded in her skin were from the carpet.
Back on the ship, Gibbs and Ellie talk to the department head and discover Maya had asked for less leave time. When they mention the possibility of an affair, at Judith’s urging, she informs them that Maya took her vows very seriously.
Tim goes to give Lyle and Walt the autopsy report on Maya and discovers that they found data from the alarm panel showing it was never activated on the weekends. Michael was not living at home from Friday to Monday.
Down in the evidence garage, where Alex is going through burglary reports, Abby uses Maya’s phone to track the IP address of where the alarm panel for their system was deactivated. Michael had deactivated the alarm three weeks earlier from Fredericksburg.
Senior goes to visit Gibbs at his home for dinner and wants his blessing to date Judith. Gibbs is more than happy to do anything to get her sights off of himself.
As this is happening, Ellie, Lyle and Nick are on stakeout. They see Michael arrive at a house with a woman. At first, they believe it is his sister until they see the couple kissing.
Ellie and Nick interview Darlene Jones, who refuses to believe Michael is married. She claims they are engaged and she is stunned to find out that she is a suspect in a murder case. Meanwhile, Alex and Gibbs interview Michael. He claims he had fallen in love with Darlene and was going to ask Maya for a divorce but she was killed before he could do so.
While Senior woos Judith, Jimmy gives Lyle surveillance footage as Taj is trying to fix the alarm panel.
Back at the bullpen, the team looks at the surveillance footage and sees Mike going through the airport. Gibbs still feels like they are missing something and takes Ellie to go back to the Sherlocks.
Meanwhile, Nick, Alex and Tim go through the unsolved burglaries, finding they all came from houses who had Voltrane systems installed. When they find out Taj could be connected, they call Lyle, who tries to subdue the electrician.
Even though Taj tries to escape, Ellie stops him from leaving. He is taken to interrogation, where he denies being involved in the murder but ends up implicating himself for the burglaries.
The team feels like they are back at square one but Gibbs still feels as though Michael is involved. He feels suspicious and goes to talk to Michael himself, telling him he thinks he got Darlene pregnant.
After he leaves, Gibbs gets a call from Senior, who was looking at surveillance footage. He talks to Gibbs about how he used to switch the labels of cigars in the airport bathroom since there were no cameras inside. They suspect that Michael got someone to pretend to be him.
Sure enough, in interrogation, even though Michael tries to deny the murder, his reaction to their story shows they are on the right track. He had paid someone to pretend to be him so he could go home and murder his wife with no one the wiser. Thinking that the person he paid off is giving a confession, Michael angrily states he should have been in Mexico, thus implicating himself in his wife’s death. However, it turns out Lyle was pretending to be the guy.
After the case is over, Senior is promoted to the Sherlocks and he tells Gibbs he is taking Judith to see Tony and Tali in Paris.