Dr. Mallard provádí pro začínající patology pitvu. Když výjme mozek, začne z něj vytékat rtuť. Mallard zjistí, že mrtvý na pitevním stole byl zabit vstříknutím tekutého olova do hlavy. I přesto, že se nejedná o námořníka, začne Gibbs a jeho tým vyšetřování. Do cesty se jim však postaví FBI.

Ukáže se, že se jedná o nedávno propuštěného vězně Hintona, na kterého zcela náhodně narazí při svém vyšetřování i FBI a který nemá prakticky žádnou minulost. Nechal mu ji vymazat tajemný muž, jenž si říká Likvidátor. Gibbs a jeho tým se spojí s FBI a se šéfem Fornellem, aby Likvidátora, který se úspěšně živí výrobou nových totožností pro mezinárodní teroristy, našli.

Ducky is demonstrating an autopsy to students and one of the students notices mercury in the brain, so it is murder.

After the credits, we see McGee and Ziva discussing something on the computer; they are talking about McGee getting a dog; there is banter about which breed and also some horse metaphors; McGee says it might help Tony get a girlfriend and he should 'get back on the horse.' Tony says he does not need advice on this subject from McGee.
Gibbs comes in and says he votes for an Australian Shepherd Dog 'because they are working dogs.' At this point he tells them about Ducky's discovery. Ducky tells them there was no autopsy, so the mercury was not detected. The County Police had gone for the obvious answer; that he was a homeless drifter who had got drunk and died in his sleep. Ducky tells them there are signs he had been in prison. He wonders who the original ME had been; Palmer has not found him. When they do catch up with him, it turns out to be an attractive female ME, Jordan Hampton. Ducky is very charming to her (therefore!). The body passed through her morgue 9 days previously.

Gibbs and Tony are in a bar / crab shack asking if anyone knew the deceased. The (pretty) waitress remembers him, but doesn't know his name.But maybe she is too interested in the questioners and should be questioned herself (they do not pursue it). Outside, Ziva stops a well-dressed woman who knows the deceased, Marvin Hinton. She turns out to be an FBI agent and Hinton to be working for the FBI. Hinton was a career felon, but when they picked him up on a tip, he had no record of all this; his previous ID had been erased and he claimed someone had been in touch to offer the service. Sothe FBI were watching Hinton (and paying him) because his identity had been erased and they wanted to find the Eraser. The Eraser is the real target; they were hoping to catch him when he provided the new ID to Hinton. The FBI agent is sad - it is her first field job. When the Eraser failed to make contact the surveillance was pulled.

The FBI agent shows the team where they used to meet, in an apartment, and they find blood and mercury. It was indeed aat the crab shack where the Eraser first made contact. Abby analyses the mercury, it is old-fashioned industrial grade.The tattoos are mysteriously confusing (tattoo equivalent of scribbling over things); there are hair samples from six women.All Hinton's contacts are women, as Tony is shown the pictures, he and the agent, Courteney, start flirting; Ziva puts an end to it by telling her she has food from the team's takeaway in her teeth.

Hinton was killed by a mercury injection in the brain; a strange MO that befits someone very hygienic and controlling, as Ziva sees the FBI agent being. So Ziva thinks it could be the FBI agent who is the baddie, seeing Hinton as standing in the way of her career. She goes through the agent's bag in the hope of finding some hair samples, but the brush is clean. Tony likes Courteney a lot, says McGee. Ziva thinks Gibbs doesn't.

Gibbs and Fornell are chatting. Gibbs asks whether Fornell is FBI or Homeland Security. After talking about the inefficiencies of e-mail, GIbbs asks Fornell whether Courteney is any good. Fornell hasn't heard of Hinton's death- the e-mail went to his spam box. He is worried. Fornell has a suspect, Kamal Konkani; was Hinton being used as a test? The NCIS angle is served by the Eraser being suspected of creating identities for terrorists; they would be undetectable at passport control when they enter the USA. But for a week there has been no surveillance. Kamal operates in a very low-tech way, maybe he killed Hinton to cover his tracks.

In MTAC Fornell briefs everyone (including Jenny); Kamal has helped a lot of terrorist attacks in Europe; Tony remarks there are a lot of Ks in his name 'Ks are funny - Courteney Krieger.' At the end of the meeting we hear Fornell bawling out his officer (Courteney). Ziva is pleased; she claims she does not like cleaning up after other people.But is the real reason that Ziva has feelings for Tony? She criticises him (to his face) for being attracted to Courteney.

In the lab, Abby has the old notes written by Kamal 12 years ago; it turns out that though they are in code, there are smudges off the cash register of an Indian restaurant. They follow this line - would he not carry on eating takeaway food from his 'home' cuisine?

Courteney asks Ziva for advice. Ziva reluctantly is nice to her, tells her mistakes are inevitable and in those cases all one can do is get back on the horse (the expression she learned at the start of the episode.) Courteney said she used to be a show-jumper; Ziva lets slip her father bred Arab horses; the two kind of bond and Courteney says: 'Do we hug now?' Ziva is still not convinced.

There are 15 Indian restaurants near where Kamal lives/ lived, but only one is within walking distance, and they know Kamal does not travel. This is the Punjab Tandoori restaurant. In order to be low-key (and for comic effect!) Tony and Courteney get a table for two undercover, but of course equipped with hidden mikes and cameras (Courteney's in her pendant.) The first photo is of someone who seems to be legally on the Immigration register. Courteney is genuinely nervous, but also because she has not dated in a while; Tony says it is the same for him, and the following priceless sequence happens:

Tony: Just pretend you like me.
Courteney: It's not that hard to pretend. (takes his hand in both of hers)
Tony: You have really soft hands

At this point Ziva shouts at him in his earpiece, he jumps and the water is knocked over his trousers. On the way to the toilet, although he misses snapping the delivery boy, he manages to photo a piece of paper with a number of delivery addresses, and when the waiter looks at him strangely, he asks for the food 'to go.' The third address turns out to be registered to Hinton's alias, Frederick le Clair. We see Gibbs and Fornell trailing the delivery boy there. He drops off the Indian food, and then as he turns, Ziva comes out of an unmarked van and bundles him inside, where Courteney and Tony are already waiting.

Fornell breaks down the door and he, Gibbs and Ziva enter the apartment; it's empty but clearly Kamal's. Cut to them standing outside with the delivery boy and asking him how Kamal is going to eat his takeaway if he is not there. The delivery boy says it's a standing order, every day paid 2 weeks in advance; he did see the customer once, and he identifies HINTON from the photo. So were Hinton and Kamal the same person? The Eraser didn't murder Hinton, the Eraser WAS Hinton?

So now they interrogate the delivery boy, Robert Graves. Is the bad guy or is he just a courier? He is clearly a clever young man, who is studying electrical engineering.

Hinton was playing the FBI, he was Kamal all along, honing his skills in prison, and using himself as a test. So why let himself be caught in the first place? Now (first Courteney) suggests this: instead of Kamal killing his client Hinton, maybe a client killed Kamal once his own past had indeed been erased. Not his, hers, says Courteney, flourishing the photos of Hinton's contacts; one of them was a client. However, if her past has been erased, how can they know anything about her? Ziva points out her modus operandi is known to them. In this case, it would be nothing to do with terrorism.

Down in autopsy, Jordan appears; Palmer is surprised, and even more so when she picks up a scalped, but when Ducky appears she suggests excising the tattoo and that this might atone for her earlier incompetence.

Now Ziva and Courteney (we are very conscious they are working as a team) track down a case of a dead man from 3 years ago in Idaho; his death seemed innocent, but when a well was dug near where he was buried the water was contaminated with mercury and this was traced to a leak from his casket. The widow turns out to be.......

the waitress from the crab shack.

So they interrogate her and she tells them Kamal knew everything about her; no wonder as he made her new ID. Fornell compliments Courteney and releases the delivery boy. Jenny tells the others that a terrorist has been found in a marine raid with a flawless fake US passport and the others in the cell have got away. So the terrorists are untraceable and on the way. But no! Ducky appears to elucidate the tattoo. Once the blue pigment has been removed, there is a tattoo of a tiger's head beneath, done by a famous Boston tattooist and datable to a particular few days. Days when Kamal was known to be in London. So what is going on?

Now the team realises the delivery boy has fooled them. Like the dread Pirate Roberts in the Princess Bride (Tony's reference), the name Kamal sells the identities but is held by different people. Is it possible Hinton was one of the Kamals, trained Robert Graves, who killed him and wanted NCIS and the FBI to think Hinton was Kamal?

Cut to Courteney dropping Robert off. and wishing him well. They are both outside the car. Ziva's phone rings- she is in the driver's seat, we see. Gibbs tells her not to drop him off. Robert realises and snatches Courteney's gun. He fires twice at Ziva, who fortunately comes out of the car very low and the bullets miss. Courteney bashes Robert's head against the car, subdues him and retrieves her weapon. Can we hug NOW? asks Courteney and this time Ziva smiles.

Now Gibbs and Fornell interrogate Robert properly. First they explain the story; there IS a real Kamal, who DID train Robert. But somehow Robert did not hide his own tracks easily enough, so Hinton realised who he was. Because Hinton would have led the FBI to Robert, Robert killed him; Robert framed Shannon (the waitress) for the Hinton murder because he knew her MO; she had been a client, after all, indeed his first one. Robert remains scornful, particularly of Kamal being a dinosaur and not being able to use a computer, but using the pretext of his shooting at Ziva, Gibbs and Fornell easily frighten Robert into giving up his client list and Kamal's identity.

Final scene is in MTAC. Gibbs, Tony and Ziva watching a surveillance video; the picture is slow to come up, but when it does, an old (Caucasian) man is arrested by Courteney and other FBI agents. When we see her, Ziva asks Tony if he got her number; he says no, but Ziva says she did, because Courteney wants lessons in learning how to fight!