"Under Covers" is the 8th episode of the third season of the American police procedural drama NCIS, and the 54th episode overall. It originally aired on CBS in the United States on November 8, 2005. The episode is written by Lee David Zlotoff and directed by Aaron Lipstadt, and was seen live by 17.79 million viewers. Several recurring characters appear, including FBI Agent Tobias Fornell (Joe Spano) and lab assistant Charles "Chip" Sterling (Michael Bellisario). The episode, which was among the first to feature the character of Israeli Mossad Officer Ziva David, centers on an undercover assignment that requires Ziva and Tony DiNozzo to impersonate two married assassins when their bodies are found. Meanwhile, an attraction between them surfaces. Plot When it is discovered that Sophie and Jean-Paul Rainier, two married assassins, who were fatally wounded in a car crash, were planning an assassination at the United States Marine Corps birthday ball, Gibbs sends Ziva and Tony to pose as the married assassins in order to find out who the couple had planned to assassinate and who had hired them. The assignment requires them to simulate sexual relations and stay in the Rainiers' hotel room in order to solidify their cover. Tony and Ziva communicate with their supposed employer while trying to identify both him and the target of the assassination. When the camera on their hotel room is traced, the team is shocked to discover that FBI agents, apparently unaware of the Rainiers' deaths, have been watching them through surveillance. The FBI is initially furious, believing the case to be in their jurisdiction, but both agencies reluctantly agree to collaborate. After the team finds out that the couple were expecting a baby and might have been planning to retire, they realize that the assassination plot could have been a set-up and that the Rainiers were potentially the real targets. Before they can be warned, Tony and Ziva are cornered, held at gunpoint, and tied to chairs for questioning. Their captors, led by a contract killer who is identified as Marcos Siazon (Eric Steinberg), demand to know the location of a disk containing coded information and funds. In hopes of allowing Ziva to escape and despite knowing that he will most likely be executed for it, Tony claims that the disk is in their hotel room and persuades Siazon to allow Ziva to be escorted back to retrieve it. Gibbs,