V antropologické laboratoři je před zraky kamer otevře doktorka Burnsová rakev z Občanské války a v ní je nalezena velmi zachovalá mrtvola muže v uniformě Unie. Vedle muže však leží mobil a je zřejmé, že muž zemřel poměrně nedávno.

Ziva z Mossadu přichází do NCIS s tím, že tam nyní bude pracovat, samotného Gibbse však tato zpráva překvapí a dochází k ostré výměně názorů se Shephardovou. Ziva musí odevzdat zbraò a její aktivity jsou omezeny pouze na pozorování dění, samozřejmě přijímá tuto skutečnost se značnou nelibostí. Pátrání ukazuje, že muž se snažil z rakve dovolat mobilem pomoc a pravou příčinou jeho smrti bylo udušení. V jeho sejfu jsou pak nalezeny cenné historické artefakty, mumifikovaná ruka se vzácným prstenem a stará mapa.

Pracovnice banky vyšetřovatelům NCIS rovněž sdělí, že o sejf se již zajímal i údajný bratr zemřelého a poskytne jim videozáznam s oním mužem. Před budovou banky je pak agentům odcizena mapa vedoucí k pokladu. Ziva však prokáže své mimořádné schopnosti z Mossadu a díky své fotografické paměti dovede vyšetřovatele k místu pokladu. Scházejí se zde milovníci historie a mezi nimi agenti zahlédnou i údajného bratra zemřelého, který před nimi začne utíkat. Na místě ukrytí pokladu Ziva s Duckym přistihne dva muže, jak vyzvedávají poklad pro doktorku Burnsovou, dochází k potyčce, Burnsová si bere Duckyho jako rukojmí. Ziva si však se situací i bez střelné zbraně poradí. Vychází najevo, že Burnsová se onoho muže zbavila proto, že chtěl předat nalezený poklad muzeu. Ziva získává respekt týmu NCIS.

This episode begins with Dr. Burns of The Smithsonian Anthropology Lab discovering a Civil War era tomb. All this is being filmed because of its antiquity and it being sealed and unopened. Once opened, the doctor discovers that the tomb isn’t really old because the body has been buried with a cell phone, certainly something not of that time (as one of the cameramen remarks).

Opening credits.

It's Monday. Tony is unshaven and in a bad mood (in fact he is shaving in the lift). There is Ziva sitting in the office and making wisecracks! What is she doing there? Ziva explains that she is here as a liaison officer for NCIS. Does Gibbs know, asks Tony? Do you think I'd be there if he didn't? McGee turns up and is equally mystified. Ziva shows them his orders signed by Jenny. Now Tony and McGee suspect Gibbs doesn't know. Gibbs turns up, has a quick flashback and indeed, he did not know.

Gibbs goes to Jenny to complain; Jenny stonewalls him. He complains she is a spy and an assassin; not an investigator; she tells him Ziva is very good, and he is lucky to have her, and also that it's his own rule (18) to act first and seek forgiveness afterwards. Gibbs says this is rich, having his own rules used against him.

Tony and Ziva are already joshing about a men's magazine (Ziva had a Hebrew version on the plane.) Gibbs comes back very hostile and says 'Pack your trash' but it's a front, Gibbs follows her into the lift to have a private word. Did Ziva ask to come? Yes, she said, she did; she doesn't know if she believes what her father said about her brother. Mossad believes that Gibbs killed Ari, not that Ziva did and Ziva says she's grateful (at the end of Season 6 we learn this may not have been true at all.) Gibbs says he does trust her; she says

McGee reports the body in the Smithsonian, he has to explain that this is not a Civil War body, but a recent one, though dressed in a Union uniform.When they arrive, it turns out that Dr Burns met Ducky 18 years ago at a conference in Hawaii; she still has the necklace he gave her; maybe they had a romantic encounter. Burns had had the body imaged; it looks as if the man was killed by a musket ball.Off they go with new member Ziva observing (i.e. without weapons - which means her main gun, her backup gun and the knife at her ankle). McGee and Tony are taking photos (with a statue of a bear) when Gibbs enters, prompting all to share what they have found out. Ziva (it's a way of indicating she apparently has no investigative training) asks why she has a bullet hole in her hat, to which Gibbs replies, ‘It’s for ventilation’. Ziva requests to drive back, so she can feel as if she has been of some use, we see her driving skills, or lack thereof. Tony and McGee are frightened, with Tony eventually throwing up on McGee. They later switch drivers to Tony.

Ziva is ordered to observe; as yet she has no tasks assigned, though she nicks Tony's sandwich.The corpse is identified as a Marine Staff Sergeant consistent with its dog tags. In autopsy Ducky finds the musket ball, but this is not how the man died. He was only wounded; but there is rust in his lungs; he was buried in the casket while he was still alive. The reason, however, he was in a Civil War uniform was that he was part of a reenactment society, that is actually re-enacting the Battle of Manassas that weekend. Gibbs grumbles to Jenny about Ziva's lack of training; but of course we can't tell how serious he is.

Abby is in a bad mood, because she has been made to wear business attire; she is also initially hostile to Ziva.The dead man had tried to claw his way out of the coffin. At first the cellphone key presses do not make sense, but then McGee realises it is a text message, but not necessarily a very illuminating one.Tony and Ziva go to search the construction site in which the tomb was found for any evidence (based on the soil on the fingernails), and come up empty handed. Ziva comes back all dirty, as Tony made her do all the work, but she can’t shower until she leaves for home (As Gibbs tells her).

From the usual computer searches, McGee and Ziva are able to locate a deposit box for the dead soldier and find some interesting artifacts in it. As they arrive, Ziva scents danger, she attributes it to unfamiliarity with the USA. They are also given a video of ‘the brother’ who has been inquiring about the box, but the bank has never allowed ‘the brother’ access to it. In the box is a mummified hand with an old ring attached and a treasure map. But they find out from the office while they are still in the bank that there is no real brother. Ziva says the hand and apparent treasure map make her feel she is in a Harry Potter novel.

As they prepare to leave the bank, McGee and Ziva are stopped by a tourist asking for directions. (This is Judd Kearns, a member of the same civil war club, who needs the map in order to find the treasure. He doesn’t seem to know about the ring, which is a good thing – as it will lead the team to the same destination!)

Kearns gets the map because he has an accomplice in ambush in a van with a gun trained on them. McGee has to surrender his weapon and he also pushes them in the pool outside. Ziva is annoyed; she says later it would not have happened if she had been allowed to have her weapons, but at least she is clean again.

Tony is stuck finding out what Oxbow and Kearns in the text message mean, when McGee remembers it was on the missing map. Gibbs is angry that that map has been stolen and to make matters worse, no photo was taken. At this point, we are shown how skilled Ziva really is as she has reconstructed the map from memory. According to her, ‘At Mossad, officers who fail to observe generally don’t last long.’ Abby is jealous when McGee compliments how talented Ziva is, but is back to work when she starts to process the hand and ring. Ducky and Dr Burns (who has apparently taken a liking to Ducky) try to understand the history of the ring, and realize it might belong to a wealthy family in Manassas. Abby offers to run the features against satellite imagery, but Dr Burns says she knows the place well.

The team, with Dr. Burns head off to Manassas Battlefield Park, where the Civil war re-enactors are gathering. This time, Gibbs makes a point of returning Ziva's weapons to her. (She smiles happily) Tony explains his father was part of one such kind of society, and made him carry round a bucket in which the 'troops' would relieve themselves. So he hates the Civil War.

At the park, Ziva, Ducky and Dr Burns head off to look for the buried treasure, specifically for landmarks. Dr Burns suggests starting near her dig sites, but Ducky says the map may be deliberately confusing and suggests starting in the opposite direction. Gibbs, Tony and McGee spot the person from the bank video (the "brother" - who is actually Kearns) who makes a run for it.

Ziva thinks that they are managing to follow the map; Dr Burns disagrees, but Ziva ignores her. The others catch the 'brother.' Where there is an x on the map, Ziva and co find a Civil War graveyard. Ziva sense danger and asks Ducky to call Gibbs butZiva’s backup will not arrive imminently, because, as we learn, Ducky isn't able to call. Ziva goes forward, gun in hand, and sees two men, one mounted in period uniform and one not in uniform, opening a casket. The casket is full of weapons; the men talk about the profits they can make from selling them as historical pieces - Ziva finishes their sentence - the weapons are worth $1.5 million. The men are captured.

Kearns claims he knew nothing about the Staff Sgt.’s death and that he was only paid to be ‘the brother.’Gibbs is on the phone but I guess what is happening is that he can't get hold of Ducky, so he knows there is something wrong. And something is wrong; as Ziva calls out to Ducky, Dr Burns appears holding Ducky at gunpoint. Ziva cannot shoot without risking Ducky, so she very carefully puts her weapon down while asking Dr Burns if it had all been about the casket of weapons.

Now we find out that Dr. Burns was behind it all with the two men who are unburying the casket filled with civil war guns and weaponry. They killed the Staff Sgt. because he found the map and casket and wanted to give it to a museum. The only mistake the conspirators made was that he had been killed before they could get the map.

Of course Ziva knows what she is doing; she has extracted the confession; she puts the gun down slowly and as Dr Burns pushes Ducky out of the way so she has a clear shot at Ziva, Ziva throws her ankle-knife (this is why a point was made about it earlier) straight in Dr Burns' heart. Dr Burns' gun goes off, alerting Gibbs and Tony to the exact whereabouts of the others. When they arrive however, they find thatZiva’s training has enabled her to kill Dr. Burns AND detain the two men, who are now prone on the ground. Tony remarks "Remind me not to piss her off." "You have no idea," Gibbs replies (and indeed in this case the match-up between Ziva and the extremely amateurish bad guys is especially unequal)

Back at the office, Ziva is sitting in Kate’s old desk. She finds Kate’s drawings of the team and tells Gibbs that ‘Kate wouldn’t mind’ – meaning Ziva is now part of the team and she should sit at Kate’s old desk. In the next episode, we see that she has now moved from the desk at the back, to Kate’s one at the front.