As season four starts the usual head of NCIS, Gibbs (played by Mark Harmon), has left for the greener grasses of retirement so Tony DiNozzo (played by Michael Weatherly) is now in charge of the team. He starts off with his hands full as one of his team members is accused of assassinating an Iranian prisoner. Soon enough they realize they need Gibbs back. And that is great for the show as Harmon brings some levity to what can sometimes become a dark show.
Episode 1: Shalom: Ziva (played by Cote de Pablo) accidentally sees a political assassination then finds out that the FBI is looking to arrest her for the murder.
Episode 2: Escaped: Gibbs has to come out of retirement to help Fornell (played by Joe Spano).
Episode 3: Singled Out: Jenny (played by Lauren Holly) makes a secret offer to Tony.
Episode 4: Faking It: An old case that Mike Franks (played by Muse Watson) worked on involving a Russian opens up again and he comes out of retirement to work on it.
Episode 5: Dead and Unburied: A missing Lance Corporel is found dead in an empty house.
Episode 6: Witch Hunt: It is Halloween and the NCIS team has their hands full with a ransom case.
Episode 7: Sandblast: NCIS joins forces with the Army Criminal Investigation Division when an explosion and subsequent death at an army golf course begins to look like a terrorist attack.
Episode 8: Once a Hero: A respected Marine veteran is found dead in a hotel and NCIS is called in to find out how he died.
Episode 9: Twisted Sister: McGee (played by Sean Murray) breaks the rules and risks his job in order to help his sister.
Episode 10: Smoked: In a chimney on a Marine base the burnt and mummified body of a missing person is found.
Episode 11: Driven: Ziva notices that Tony keeps visiting the hospital and wonders why.
Episode 12: Suspicion: Gibbs investigates a case involving the murder of an intelligence agent and wonders whether it was a terrorist act.
Episode 13: Sharif Returns: Known terrorist Mamoun Sharif (played by Enzo Cilenti) has 10 kilograms of very toxic chemical weapons in his possession.
Episode 14: Blowback: NCIS finds out that another government agency with a completely different agenda is working on the same case as them.
Episode 15: Friends & Lovers: While working on the case of a sailor who has died of an apparent drug overdose Tony gets close to a local detective.
Episode 16: Dead Man Walking: A Navy lieutenant is the victim of radiation poisoning NCIS is called in to find out who is responsible.
Episode 17: Skeletons: An explosion at a military cemetery unearths a mixture of body parts.
Episode 18: Iceman: A frozen marine who is supposed to be dead and is on Ducky’s (played by David McCallum) autopsy table when he suddenly turns out to be alive.
Episode 19: Grace Period: When two agents are killed during a terrorist attack that the government was tipped off about, Agent Paula Cassidy (played by Jessica Steen) feels guilty.
Episode 20: Cover Story: McGee is under pressure to solve a case in which he has very little to go on.
Episode 21: Brothers in Arms: Director Shepard makes the mistake of meeting an informant who has information on Le Grenouille alone and that informant ends up dead.
Episode 22: In the Dark: Gibbs and Tony are both having relationship problems.
Episode 23: Trojan Horse: Jenny is off to an overseas conference and Gibbs is named acting director.
Episode 24: Angel of Death: Jenny is back and is going to force each member of the NCIS team to take polygraph test in which all their secrets will be laid bare.
Special Features: Cast roundtable (parts 1 & 2), Ducky’s World, Behind the Set: The Production Design of NCIS, Dressed to Kill: Dressing the Sets of NCIS , Prop master, Picture Perfect: The Looks of NCIS, Season of Secrets