This latest episode of NCIS begins with a little girl walking home with her neighbor, Mr. Curtis, and his son, Benjamin. Rachel is discussing her Harry Potter costume with them as they arrive at the house. She goes inside and just as Mr. Curtis and Benjamin are about to walk home, they hear Rachel scream. Mr. Curtis goes inside to check on her, only to find her mother dead on the floor covered in blood.
In the squad room, Ellie and Tim are having a heated discussion when Tony comes in to break it up. However, he is surprised to discover Ellie doesn’t want to wear a costume to Abby’s party and Tony tells her Abby would not be happy. Tim describes a previous Halloween when he told Abby he didn’t want to carve a pumpkin. Ellie reveals she and her husband can’t decide on a costume and Tony laments on the holiday being a couple’s paradise. When pressed on bringing someone, he doesn’t remember his previous date, which is the sixth this month. Gibbs comes to tell them about the dead woman.
The victim is Dr. Valerie Barnes and she is married to a navy commander named Ryan Barnes. She has a single gunshot wound to the back and died between midnight and 2 in the morning. Outside, Tim talks to Mr. Curtis, who tells him that Valerie dropped Rachel off at his house at six the night before and the husband left for a mission a few days earlier. He asks about Rachel, who is in the backyard.
Gibbs goes to talk to Rachel, who is inside a fort she built with her dad. Rachel doesn’t want to leave the fort in case “they” come back and she tells Gibbs people are after her dad.
In the squad room, Ellie is discussing her list of couple costumes with Tony and Tim, but when they list off the usual costumes after telling her to go for something crazy, she throws it away. Gibbs comes for an update and they tell him Valerie has not had any issues with patients in her work and Tim found out Ryan Barnes was part of the mission to capture Benham Parsa. The names of the SEAL’s were leaked and there is a website with a hit list on Ryan.
Ellie, Abby, and Tim are working in Abby’s lab, where a toy hand is coming after Ellie’s laptop. Tim and Abby find that the hit list came from a man named Dorian Hobart, who was dishonorably discharged and has joined antigovernment groups. They decide to use a cover in order to meet with Hobart and when Tim tries to use the name Dylan, Abby says he can’t pull it off so Ellie comes up with Tim Walsh to try and stay close to the truth about who he is.
In the interview room, Gibbs brings popcorn and hot chocolate for Rachel, who has been hiding under the table. He tells her about his mom dying when he was close to her age. Rachel is angry that her mom didn’t do enough to stay safe since her dad told them to be on alert and she says she did. She wants her safe place, so Gibbs brings out a box so they can build a fort.
Ducky and Tony are in autopsy where Ducky tells him that Valerie died instantly and he found she had an old eye socket injury. Ellie comes to tell Tony that Hobart took the bait and is meeting Tim at the park.
At the park, Tony and Ellie are doing yoga poses while McGee sits on a bench with Gibbs nearby. As Hobart looks at a bag Tim shows him, the team moves in. However, a woman comes and knocks Tim down. When Tony calls out, she recognizes him and calls him ‘Spider.’ Tony tells a surprised Gibbs that she worked in the Philadelphia police department but she tells him she’s know ATF Agent Keates. Tony tells her they are taking down a terrorist, and she reveals it’s her.
Hobart is actual Agent Marston, who plays as a decoy. It turns out they had captured Hobart months ago and only kept the website up to keep it looking authentic. Gibbs is not thrilled since Valerie is dead, but Keates points out that if she had made a mistake, she’d admit it. Plus, since Valerie was only killed with a .38 caliber gun, then it wasn’t an extremist group since they would be more dramatic with their killing.
While Gibbs takes a phone call, Tim comes over with an ice pack over his ribs. Keates apologizes and Tony mentions she has always been aggressive. She reveals that his nickname is ‘Spider’ and she was a rookie with Tony in Philadelphia. Keates also brings up how Tony always ran from commitment. Gibbs gets off the phone to let them know Commander Barnes is on his way.
Commander Barnes views his wife’s body and is very upset. Gibbs tells him his wife could have been targeted. Barnes tells him to find the killer before he does, but Gibbs reminds him to focus on Rachel.
Tim comes in to Abby’s lab and she throws a heating pad at him. He looks at Ellie, who defends herself saying Abby wanted an update. She had also told Abby about Keates and Tony, and she used dummies to show Abby their body language. They realize the two have serious history and Tim tells Abby he hasn’t seen Tony like that since…but he doesn’t say the name, although we know he means Ziva. Ellie doesn’t find out who Tim meant, but she mentions they could help Tony move toward Keates.
The subject changes to the bullet, which fragmented due to faulty storage. Abby will be able to make a 3D image of the bullet once she gets photos back of the crime scene. In the squad room, Gibbs is walking with Ryan and Rachel, who will be at the Admiral Heights hotel until they can get back home. Rachel is very chipper as she goes with her dad.
Tony tells Gibbs that Valerie used to work at a forensic psychiatric hospital and when she was working with a serial killer named George Burton, he managed to attack her, which is where her eye injury came from. He is serving a life sentence at a psychiatric hospital, so he’s not the killer, but Valerie did visit him two weeks prior to her death.
Gibbs and Tony pay Burton a visit and when he discovers Gibbs is with NCIS, he figures Valerie is dead. He tells them he wouldn’t hurt Valerie since he had respect for her, but Gibbs points out the photo of the old injury to her face. Burton reveals he only thought it’d help with his insanity plea. He tells them that Valerie came to him because she was scared about another patient, who reminded her of him since the person is also a sociopath. He tells them a sociopath will tell lies to get what they want and if someone becomes an obstacle to what they want, then they will get rid of the obstacle.
Back at the squad room, Ellie is falling asleep while going through patient files. The only possible violent patients she had all have solid alibis. Keates comes in to give a peace offering, with coffee and a muffin for Tim. She confirms there has been nothing said about their victim in extremist circles. Ellie goes to ask Keates about classic movies, but she accidentally makes it sound like she’s asking Keates out.
Abby brings Tony down to her lab where she gives him a hug and then tries to talk about what has been going on the past year. Tony says he’s happy, but Abby knows he is acting and tells him to say Ziva’s name. Abby reminds him that she may never come back and they may love her, but he has to move on and face reality. Tony says it’s not any easier and he does admit to missing his friend.
The ballistics come back and Abby finds it was in the system for a previous accidental shooting by Nathan Curtis, the victim’s neighbor. Nathan is in interrogation and he is surprised his gun is the one that was used in the murder. Tim tells him to talk and Nathan tells them that he tried to commit suicide with the gun. He didn’t want the gun in his home anymore so he gave it to Valerie to keep it in a safe. Nathan tells them that he saw Rachel with bruises and he asked Valerie about it, thinking Ryan did it, but Valerie said he didn’t do it.
Ellie comes for Gibbs to tell him that no one could account for Ryan’s whereabouts between 11:00 PM and 3:00 AM the night of the murder. He was only 12 miles away from the house, so it’s possible he committed the murder. Ellie goes to get Tony so they can bring him in. They go to the hotel where they find out no one has seen Ryan or Rachel since the day before. Tony is surprised since he didn’t see that it could be the spouse this time. They go into the hotel room, but find it is empty and it doesn’t look like anyone slept in there.
Tim hasn’t found any activity on Ryan’s cards or cell phone and Ellie reminds him that Rachel may have a phone. Tony tells them that all transportation spots are on alert. Tim finds activity on Rachel’s cell phone, where they are at a rest stop.
They go to the rest stop where Ryan and Rachel are sitting at a picnic table. Ryan looks stoic as Rachel cries beside him, wanting to go home. The team holds their weapons out and Ryan gets up, confessing to killing his wife as Ellie pulls Rachel away. However, Gibbs has an unsure look on his face.
Gibbs goes to see Ducky to tell him he has a feeling in his gut. So does Ducky, who shows him Rachel’s medical records. She was the victim of abuse, but her dad was overseas during the time she was abused. Gibbs remarks that George Burton told them that sociopaths would do anything in order to get what they wanted. Ducky, who still thinks Ryan killed Valerie, says he doesn’t exhibit signs of being a sociopath and Gibbs realizes he’s not the killer.
In the interrogation room, Gibbs sits down across from Rachel. She plays dumb, until Gibbs shows her the gun that she buried under her fort. Rachel tells Gibbs she didn’t have time to bury it all the way down since she had to get back to Nathan’s house before he noticed she left. She tells Gibbs she hated her mother because she was trying to get her some treatment, but Rachel says she didn’t need help. When her dad was around, things were fine. She would hurt herself so he’d come home and the only way to make her stay was to kill her mom. Her dad watches the interview from the other room with Ellie.
Back to the squad room, Tony is dressed as Bruce Wayne, but Tim is annoyed since he was supposed to go as Batman to his Robin. They turn to see Ellie, who is dressed as Sandy from the ending of Grease. Tim and Ellie leave while Tony stays to finish up at the office. He takes out a Star of David necklace as Keates comes in. They talk about their past and Tony wonders why she didn’t contact him, but she reminds him he left and never said where he was. However, she does tell him she knows he needed to find his way and he apologizes. They leave to go take a walk. When she calls him ‘spider,’ he gives her a slight kick to the behind.