Two NCIS agents, Jim Nelson and Rick Hall, are sitting in an outside café, waiting for a person who gave them an anonymous tip to show up. The mysterious man calls Paula Cassidy, who is sitting in a car, telling her that he’ll meet with her contacts in a nearby building. The team spots the man, sporting a beard and sunglasses, walk into the building. The two agents follow him into the building, but when Cassidy pulls up, the building explodes.
Gibbs, on a date with Colonel Mann at a batting cage, gets the call and immediately rounds up the rest of the team to the place of the explosion. Ducky proposes that the man who was in the store was a suicide bomber, which confuses the team. Cassidy is pulled aside by Gibbs, who tries to convince Cassidy to stay focused. McGee ruminates that he knew Jim Nelson, and Gibbs tells the team that it could have been them – they were supposed to pull weekend duty that weekend. Two men, Wahid and Malik, come to the store, telling the team that they are part of The Muslim Coalition for Peace. Ziva finds the head of the suicide bomber, and Wahid and Malik tell the team that it is the head of their chapter president, Yazid Fahad. Yazid was planning a conference on Friday, bringing together Shia and Sunni clerics that will issue fatwas condemning suicide bombing in Iraq – taking out the clerics would be a major blow to peace.
At Abby’s lab, Abby tells Gibbs and Cassidy that Yazid was a former sailor in the U.S. Navy, and that the two calls he made to NCIS match. However, Ducky tells Gibbs and Cassidy that, based on decay in the brain tissue, Yazid was dead at least one day before the bombing, the victim of strangulation. Cassidy still angrily says that Ducky must have been mistaken. The argument is broken up by Gibbs, who tells DiNozzo to take Cassidy back to the crime scene, to see how a bomber could have gotten out before the explosion. While looking around at the crime scene, DiNozzo tells Cassidy about his rock-climbing date with Jeanne, and how he couldn’t bring himself to tell her ‘I love you’. Cassidy tells DiNozzo that he needs to step up and say it before it’s too late.
Back at NCIS, Abby shows Gibbs a call Yazid made on Friday to NCIS, which she traces to Kirtek Computing – a place that makes software for disabled people, and where Yazid worked. Gibbs, Ziva and McGee talk to Mr. Abu Selom, the owner of the company, who agrees to let the team talk to the employees. However, none of the employees has a match to the voice of the calls made on Sunday. Based on a DVD Yazid made for his company, the voice matches Yazid’s – meaning he must have somehow have been alive at the time of the bombing.
Based on the fact that the bomber could have had only 12 seconds or so to get out of the building, DiNozzo comes up with a trick he saw in an old monster movie – he lights a cigar and blows smoke against the walls, eventually finding a trick wall where the bomber ducked into before the explosion. The wall is adjacent to another store, both of which used to be part of a magic shop. In the adjacent shop, shards of the sunglasses of the man who ran through are seen on the floor.
In Ducky’s lab, Ducky finds traces of latex in Yazid’s throat. At Gibb’s house, Colonel Mann shows up with some Chinese food. While eating, she tells Gibbs that she’s contemplating retiring from the CID in the next month, making time for ‘the people in my life’. At the office, Abby reveals that the fingerprint she got from the sunglasses are from Salman Umar, one of the employees at Kirtek Computing. However, when the team get to the office, Umar opens fire on them, causing the team to kill him in self defense. At Umar’s desk, they find software on a laptop that Umar was working on – by using a 3-D model of the vocal cords, the voice was able to duplicate Yazid’s. Umar poured hot wax down Yazid’s throat and mouth and cast a mold using the latex, and used the mold as a template for Yazid's voice. However, Cassidy doesn’t recall the man she saw carrying a laptop, which he would have needed to use to make the call.
The conference continues to go forward, with a special memorial for Yazid at the building that blew up held by high-ranking Muslim clerics, who Gibbs figures to be the real targets. At the office, Abby finds matches for three fingerprints on Umar’s laptop (isolating the fingerprints on the J and F keys, since she says that is where people’s fingers rest before typing). McGee calls Gibbs as the memorial service starts. Gibbs starts to arrest Wahid, but Malik comes out from behind the trick wall, primed with explosives on his chest. Cassidy jumps and tackles Malik, throwing him back behind the wall, and the door automatically closes behind them. Cassidy sees the images of Jim Nelson and Rick Hall just as Malik sets off the explosion, killing himself and Cassidy but only shaking the room the rest are in. A clearly shaken and possibly heartbroken DiNozzo later shows up at Jeanne’s apartment (with the R.E.M. song “Everybody Hurts” in the background), and tells her he loves her, then gives her a hug whilst crying because of the death of Cassidy, which has made the situation real, this may be a reference to the prior talk where Cassidy told DiNozzo, you have to own up to loving someone, before they're gone.
Ziva is once again seen wearing the orange cap she started wearing in the last episode, but no mention is otherwise made of this. The orange cap is the cap Lt. Sanders wore in Dead Man Walking and Ziva wore it because she fell in love with him before he died of radiation poisoning.
Although Jimmy Palmer, Ducky's assistant, doesn't appear in this episode, Ducky makes mention of how Mr. Palmer has gone missing again, continuing the running joke throughout Season 4 of Jimmy's sneaking off to have sex with Agent Lee.