On "Jet Lag," Tony and Ziva travel to Paris to escort key witness, Nora Williams, back to the U.S.

She will be testifying against her employer, Ray Bolinger, a major military contractor, who is accused of extorting millions from the Navy, billing them for unnecessary repairs needed on their ships.

No one knows she is going to testify, supposedly, but Tony and Ziva fear for her life - and for good reason. A Marine who was moonlighting as a hit man is found dead and was tracking Williams.

Gibbs and McGee work the murder of Petty Officer Jeff Parsons, who was found dead in his expensive apartment. Parson’s safe reveals that there was more to him than just his Navy day job.

He was an assassin whose next job was Nora Williams.

Whoever killed Parsons was another pro, they determine, who wanted to take over the job of killing Nora and receive the huge payout for themselves. A hit man offed by another hit man.

Parsons' phone records lead NCIS to a well-known madam who, rather than matching buyers and sellers for sex, was apparently doing the same for other services, such as contract killings.

She wants a plea deal and eventually gets it in exchange for her bank records.

On the flight, Tony and Ziva keep watch over anyone who looks suspicious.

They suspect the federal air Marshall, who pulled strings to get on this flight, may be their man ... until he is found dead in the bathroom and his gun is stolen.

Thanks to a bloody print on a crochet needle used to stab him to death, and Abby's awesomeness, they are willing to connect the dots: it's a flight attendant.

She was a contract killer who was hired by none other than Nora’s fiancée - who also worked for Bolinger as an accountant - to take her out.

Instead, Ziva takes her out.

The fiance's motive? Nora was going to expose him, too, by testifying, as he was stealing from the company (which was stealing from the government).