Three teens wearing monkey Halloween masks, "See, Speak and Hear" No Evil, are causing mischief in their neighborhood the night before Halloween. They toilet paper trees in someone's yard and run when they think someone is coming. One of the boys has been video taping their activities. They race across the street and hide behind a truck until they think it’s safe. One of the boys hears a car running behind them with music blasting. They realize it’s their neighbor and think he’s having a little fun in his car. They quietly walk up to the car and one boy throws a water balloon at the window. When they get no response, they assume the man is sleeping or he's high because the car is full of smoke. They realize the man still isn’t responding so one boy goes around the car and sees a hose rigged from the exhaust into the car. They knock on the window then open the door. The neighbor falls out, dead.

Tony walks into the squadroom on the phone. He’s making a bet with a friend on the Baltimore, PD for “Larceny Lotto.” It’s an old tradition, all the cops toss $200 each into the lotto and guess how much mischief will happen on Halloween eve. McGee reminds Tony he hates Halloween but Tony doesn’t care, he loves money. Ziva realizes the mischief is why someone kept ringing her doorbell and running off all night. McGee share a story of how he and some buddies took all the bedroom furniture out of the Base Commander’s home and put it out on the tarmac. Gibbs walks in and says, “Lock and load. We got a dead marine.” He grabs the keys, tosses them to Ziva calling her “Agent David.” Ziva smiles as she catches the keys.

At the victim's house, the team is processing the crime scene. The deceased’s name is Marine Lance Corporal James Korby. Korby just got back from his third tour in Afghanistan and lives with his wife and stepdaughter. Ziva points out there is no blood or sign of a struggle, so all evidence points to suicide. Ducky corrects her and says Korby didn't die of carbon monoxide poisoning. If he did, his skin would be cherry red. The crime scene was staged to look like a suicide.

Tony questions the three teens. When Ziva starts to ask a question, he tells her he’ll handle it and calls her “probie.” One of the boys talks about how Korby lived for Halloween. He created all kinds of jokes and pranks just for Halloween. A neighbor, Ted Rogers, in a nice reddish sweater and tie, is standing nearby and says the pranks were illegal. He complains about Korby’s pranks, and now Korby’s gone and died in his yard. “Well it sounds like you’ve got a problem in your neighborhood Mr. Rogers. That’s a nice sweater by the way,” Tony says. Ziva tells the boys she’ll need the video tape. Mr. Rogers tells her they can use it as evidence for the mischief the boys caused. Tony says they are only interested in Korby’s death and dismisses Mr. Rogers.

Gibbs walks up to Ducky as he’s checking the temperature on the body. Gibbs asks Ducky for the time of death but Ducky can’t provide it. He is puzzled because the body should be very warm due to the heat from the carbon monoxide but it’s frigid. He needs to get the body back to autopsy in order to figure out the time and cause of death.

Tony and Ziva go into Korby’s garage and find what Tony refers to as “the joke lab.” It’s full of all kinds of Halloween paraphernalia. Ziva notices the garage is a mess. Tony says jokesters don’t trash their own stuff, its part of the crime scene. A computer monitor is broken on the floor, which shows signs of a struggle.

The body has been removed from the car and is sitting upright on the hood. Ducky and Palmer go to move the body when they hear a noise coming from inside it. Gibbs asks Ducky what it is but Ducky doesn’t know. Even in full rigor, the body wouldn’t be brittle. Ducky asks Palmer to help him lie the body down. As they straighten out the body, they hear the noise inside the body again. Ducky asks Palmer for forceps and puts his hand on the victim’s chest, making more noises. Ducky uses the forceps and reaches inside the victim’s mouth, pulling out a piece of his throat, which is completely frozen. Palmer asks what could get something that frozen, and suggests dry ice. “Or liquid nitrogen,” Ducky replies. “I think you found your cause of death” Ducky tells Gibbs.

In the squadroom the next morning, Tony is looking up the tally of disturbances to see where he stands in the Larceny Lotto. McGee closes his desk drawer and says, “Tony, how about we focus on a crime in our jurisdiction.” Tony stands up, walks over to McGee and says, “Thrill me, McGoblin.” McGee pulls up Korby’s information on the big screen. Korby has no criminal record and one big blemish on his military record. He wasn’t promoted due to dereliction of duty. McGee pulls up the photo of Korby’s wife, Sara. Tony says Korby didn’t kill himself. Ziva, whose on the phone, puts her hand on the receiver and asks how Tony knows. Tony says, "Any man married to that woman wouldn’t kill himself; she’s too attractive. The wife did it.” McGee replies, “Should we even bother investigating or should we arrest her.” Tony likes McGee’s thinking. Ziva hangs up and wants to know if Tony even knows where the wife was the night of the murder. She informs Tony that the wife and stepdaughter were at a spa and they are on their way in to identify the body. The elevator bell chimes and three people walk off into the squadroom. Tony continues with his theory of how the wife did it and stops when he hears a woman say, “Excuse me.” Turning around, Tony faces Sara Korby, while behind him, her photo is on the big screen.


Tony questions Sara and her daughter, Rachael, in the conference room. Sara claims she was in Virginia Beach at a spa and Rachael was at a friend’s house. Tony asks about any problems or enemies that Sara is aware of. She tells him no. Sara says that she and Korby had an arrangement because of his love for Halloween. He would spend time working on his projects for the day while she spent the night at a spa. She didn’t want to go this year because he’d just gotten back from Afghanistan. Tony questions Rachael about her stepfather. Rachael informs him that both Sara and Korby are her stepparents. Sara was married to Rachael’s father but he was killed in Iraq 5 years ago. She got remarried to James Korby. Rachael says everyone liked James even if they didn’t get his sense of humor. Tony asks about their neighbor, Ted Rogers. Sara says Ted complained about everything. When he’d learned that James was back, the two men had words.

In autopsy, Ducky remarks how Korby’s death is a ghoulish way to go. Palmer says, “It’s a cool way to go.” He tries to make a Halloween joke about how Korby died which makes Ducky question if Palmer is making light of the Lance Corporal’s demise. Gibbs walks in and Ducky tells him the cause of death was ingestion of liquid nitrogen. When it comes into contact with warm material, it literally boils. Palmer demonstrates by pouring liquid nitrogen into a pumpkin, then putting the top back on to seal it. Korby didn’t die from the nitrogen, he died from breathing. When he took a breathe, the nitrogen gas went into his lungs, killing him. Palmer demonstrates again, by taking the top off the pumpkin. Ducky says there was also scar tissue on the back of Korby’s throat but it was from something that happened prior to his death. He sent samples to Abby to find out what the cause was. Ducky tells Gibbs it wasn’t suicide, more than likely Korby was force fed the liquid nitrogen. Palmer picks up the pumpkin to move it, but drops it instead, shattering it on the floor.

In the squadroom, McGee and Ziva are reviewing the video tape footage from the three teens. McGee is commenting on the boys technique in throwing toilet paper in the trees. Ziva doesn’t see the humor in the American tradition. Tony is hanging up the phone when Gibbs walks in with three coffee cups. He hands each of them a cup and Tony is excited Gibbs brought them coffee until he smells it. Gibbs says, “Nope, apple cider. Happy Halloween.” As they begin to sip from their cups, Gibbs stands up and says, “breaks over.” McGee shows him part of the video while Ziva tells him that multiple neighbors filed complaints against Korby. Tony says, “And only one neighbor filed multiple complaints, Mr. Rogers.” Tony comments about the taste of the cider when Gibbs walks over, takes his cup, then Ziva’s, and sends them back to question Mr. Rogers.

Ziva knocks on Mr. Rogers door. He yells out for them to go away, there’s no candy in there. Ziva replies, “We’re NCIS, we don’t want any candy.” Tony tells her to speak for herself. Mr. Rogers opens the door with his tie and sweater on, an earpiece in his left ear and holding an energy drink. “Very convincing nerd outfit,” Tony says. Mr. Rogers tells them it’s how he dresses for work. Ziva asks if he’s going to work now. Mr. Rogers tells them he works from home. He’s a commodities trader and his work is just beginning. Tony points out that his porch light is on, which is a sign he’s handing out candy. Rogers goes inside and turns it off. “Your girlfriend in college got a restraining order against you, so I’m guessing there’s a temper underneath that cardigan,” Tony says. Ziva tells him they have a witness who says Rogers confronted Korby. Rogers is upset and wants to know if they are accusing him of murder. Tony replies, “No, we’re just asking you really nicely if you did it. So, Mr. Rogers did you kill your neighbor?” Rogers says no. He tells them he was online on his computer, live, with their office in Shanghai. Two twin girls dressed as ballerina’s walk up trick-or-treating. Mr. Rogers isn’t happy but goes into his house, comes out and drops an energy drink into each of their bags. The girls look don't look pleased and walk away. Tony tells them it’s just what the girls needed, their parents are going to love it.

Gibbs walks into Abby’s lab, which is full of Korby’ Halloween decorations. They are all motion censored so they go off when Gibbs walks in, making a lot of scary noises. Abby tells Gibbs to move slowly so they aren’t activated. Gibbs slows down until the decorations turn off. He remarks how she’s not wearing a costume this year. “After last year’s Jonas brothers debacle, Vance banned costumes. McGee in skinny jeans, didn’t work,” Abby replies. Abby pulls up the video the teens had taken. While she didn’t see anyone, she points out a car that drove through at the time of death. She wasn’t able to get a plate number but she was able to pull up a delivery number. Gibbs is happy with this as all Military vehicles can only be signed out by a Marine and it's a military vehicle. As Gibbs goes to walk out, all the decorations go off. Abby wants him to come back because she has more. In addition to the liquid nitrogen, she found traces of turpentine, acetone and benzene in his flesh. Someone tried to kill Korby before his actual death. The poisoning goes back to when Korby was in Afghanistan.

Tony walks into the squadroom. He sees McGee has a bag of candy on his desk and teases him that nobody showed up at his house to trick-or-treat. Tony still claims the wife did it because she was married three times, all to Marines and all three died. Ziva tells him that two of the men died while on active duty in Afghanistan. Gibbs walks in and asks Tony if he has proof. When Tony says he doesn’t, Gibbs tells him to stop talking. McGee checked the records with motor pool and the military vehicle wasn’t signed out and is still missing. They are unable to pull up the records from the team’s tour as they’d only been back 72 hours.

Korby's Unit Commander, Marine Sergeant Ross Barnes shows up and is brought into the conference room. Ziva and Gibbs point out that Barnes wrote negative information in Korby's file. Barnes says he also wrote what a good Marine he was as well. “What’s funny in boot camp isn’t always funny in the line of fire," Gibbs says. Barnes says half the guys loved Korby, the other not so much. He mentions Korby was ill a few days, they thought it was a stomach virus. When Gibbs asks for Barnes alibi, he tells them that he was being debriefed. Gibbs wants a name of anyone Korby had problems with in the unit. Barnes hesitates and offers nothing. Gibbs knows he's lying, so he tells Barnes they will have to hold and interrogate everyone in the unit. He pushes Barnes buttons when he leans down and tells Ziva to hold all promotions. As Gibbs starts to walk out, Barnes calls out for him to wait. He tells Gibbs that Private David Singer and Korby had a falling out, but doesn't want Gibbs to let on it came from him.

Tony and Gibbs visit the base and find Private Singer working out. They inform Singer that Korby is dead and Gibbs asks Singer for his alibi. Singer tells them he was visiting a friend. Gibbs asks for a name and is greeted with silence. “Those things on the side of your head work? The man asked you a question," Tony says. Tony manages to antagonize Singer, who complains how Korby was always playing jokes while others were getting killed. Singer finally gives up a name, Chris Norton, a high school buddy, is who he was with the night of Korby's death. When Gibbs returns to the squadroom, McGee tells him he put together a brief history of Korby’s unit. The unit was in chaos, there was a either a lack of leadership/discipline or too much discipline.

In autopsy, Palmer and Ducky are going through what was in Korby's lungs. Gibbs walks in so Ducky sends Palmer up to Abby with the lung samples. Korby was beaten and Ducky found multiple contusions on the body. None of the injuries are obvious to the observer, all hidden underneath so they can't be seen. Gibbs realizes somebody ordered a “Code Red” on Korby. At least 4 assailants delivered blows to Korby. "The whole squad wanted this guy gone," Gibbs tells Ducky.

Tony leads McGee and Ziva through the squadroom, a "mobile camp fire" he calls it. He stops outside a door, opens it and says, “Probies, talk louder, so I can hear you in there." Tony walks into the men's room. Ziva yells that she's been with NCIS for 4 years and McGee 6 so they are not "Probies." Gibbs walks out and informs her she was a Mossad Liaison for those 4 years, she's only been an agent for a week. He walks the mobile camp fire back to their desks. The team ran down the names of all the men in Korby's unit. They got 6 hits on men in the unit who were in the area the night of Korby's murder. Ziva and McGee are sent out to get alibi's on the 6 men.

Gibbs returns to Abby's lab. She is excited because Korby documented every prank he did on his cell phone. She processed all his toys, no murder eweapon yet. Palmer walks in, returning the liquid nitrogen. Suddenly, Abby's computer beeps so the three go to view the results. Three substances were found in Korby's lungs but not his stomach: chicken stock, coffee beans and cocoa. Palmer points out that the gas from the liquid nitrogen would carry it into his lungs. There could have been food residue on the inside of the container the nitrogen gas was carried in, like a thermos. Gibbs tells them both good work, kisses Abby's cheek and hands her her Caf-Pow, then head slaps Palmer before walking out. Abby already has the HazMat crew going through the trash at the dump yard and now she knows to narrow it down to a thermos as the item they are looking for.

Tony returns to Korby's house and finds Rachael and Sara boxing stuff up and cleaning out the garage. He asks if they are cleaning up the crime scene. Sara says she's sweeping away old memories. He asks Sara if Korby talked to her about what was going on, any problems in Afghanistan or poisoning. She tells him she doesn't know anything. Tony accuses her of marrying men who tend to die with decent life insurance policies. Sara gets upset and says she marries fighting men who are loyal and dependent. Private Singer shows up with flowers for Sara. He hands them to her and offers his condolences. Tony hangs around and watches the exchange until Sara dismisses him.

McGee walks into the squadroom and sees Tony staring at the ceiling. He asks Tony if the sky is falling. Tony says he might be wrong, the widow didn't do it. Gibbs comes in and asks Tony if he's on duty. They bring Gibbs up to speed and discover that Barnes lied. He logged out of base on the night of Korby's murder and his record shows he was denied a promotion 3 months prior to Korby's death. Ziva and Tony go get Barnes to bring him in.

In interrogation, Gibbs questions Barnes. Gibbs tells Barnes that he knows Korby caused him a promotion. "Man up Marine," Gibbs says. Barnes admits he knew about the code red, he thought it would set Korby straight but it didn’t. There was an accident, which caused Korby's flack jacket to end up on fire, which would have given their position away. While he knew it was an accident, the others didn't see it that way. They thought it was another prank. Barnes admits he put a drop of paint thinner in Korby's coffee to make him sick and get him shipped home. He claims he was doing it for Korby's safety. The guys found out what Barnes had done and the unit fell apart. They lost faith in their leadership. Gibbs asks Korby for his alibi. Barnes pulls out a business card for a strip bar. He says he was at the bar all night, ask the barmaid, meeting with his seniors to get his promotion back on track. The team checks out his alibi and discover Barnes is telling the truth, he was at the bar until 2:00am.

When Gibbs returns to the squadroom, McGee tells him he ran financials on all the men in the unit. None of them were flagged except for Private Singer. On the night of the murder, Private Singer wasn't where he claimed. He has a room service charge at the same hotel Sara Korby was at. After a phone call to the hotel, they discover the missing military vehicle is there. They bring Singer in for interrogation. Tony gets the pleasure of interrogating him but, Singer won't give up any information on Sara Korby. Tony accuses him of bringing the military vehicle, checking it out of valet parking and returning it the next morning. Singer remains silent. Another run on financials and the team discovers the hose and duct tape used on Korby's car were both brand new. A run on Sara Korby's credit card purchases shows she bought the two items the week before the murder. She is brought in for interrogation. Gibbs interrogates Sara with Tony standing in the room. Gibbs tells her he knows about her affair with Private Singer. Crying, Sara wants to know if Singer told them. Sara finally admits she couldn't go through with the affair. Korby had a service pick her up and bring her to the hotel, so she didn't have her car. She took Singer's military vehicle and drove home to tell her husband. She lost her nerve and left. She returned to the hotel and broke it off with Singer. Sara insists she didn't kill her husband. Gibbs tells her maybe Singer didn't get the message. Tony begins to read Sara her rights and arrest her for the murder of her husband. Gibbs looks down at the crime scene photos of Korby's car and says "No." He tells Tony she didn't do it and Gibbs wants him to go the evidence garage.

In the squadroom, Gibbs has McGee pull up footage from the video the teens took. He reviews where the vehicles were parked the night of Korby's death. Gibbs joins Ziva and Tony in the evidence garage. He has Tony get into the driver's seat, but Tony can't because the seat is to far forward. Gibbs shows him the crime scene photo, which shows Korby was wedged into the driver's seat. Korby's car was also parked on the street at the beginning of the video taping but was found in the driveway by the teens.

At her house, Rachael walks into the garage and calls out to Sara about a text she received, while pushing the garage door opener. In the driveway, Gibbs and Tony are leaning against their car. Rachael wants to know where Sara is but Gibbs says he sent the text. Tony holds up some paperwork and they set the stage on how Rachael killed her stepfather. When Rachael's biological father died in Iraq, he left her a trust fund of $200,000 with Sara as the executor. Rachael has 5 more years to go before she can legally touch the money. With Sara out of the way, the money is all Rachael's. Korby also has a life insurance policy for $200,000, which would go to Rachael also if Sara is in jail. Tony holds up the thermos they found in Rachael's friends house in the trash. Rachael slipped out the night of the party, everybody was drunk so nobody saw her. When she returned, she tossed the thermos in the trash. When they arrest her, she asks what happens to her money. "It's going to go a long way in the prison gift shop," Tony tells her.

In the squadroom the next morning, McGee walks in. Ziva is sitting at her desk and hands him a cup of coffee. McGee thanks her, sits down as his desk and begins to type. His keyboard isn't working and suddenly foam comes pouring out of it. He blames Abby for the prank. Tony comes sauntering in, smiling because he won the Larceny Lott. He claims he gave it to charity, an urban youth group. Ziva takes another coffee cup off her desk and walks over to Tony. She acknowledges her place with the team and that Tony is the senior field agent. She hands him the coffee and sits back down. Tony thanks her, sips the coffee and smiles. His teeth are blue.....