Season 4: Episode 24 - Angel of Death

Angel of Death: Armed with new information from a Russian officer about her deceased father, Director Shepard returns home from an international conference to discover someone has broken in to her private study. She takes heed of the Russian's insistence that her father was not the upstanding officer he appeared to be, and that he was still alive, as she notes the items that are out of place, items that her "dead" father was familiar with. She turns to Gibbs' team for help investigating, frustrating them by offering little explanation as to why they are investigating. Meanwhile, Tony and his doctor girlfriend, Jeanne, have an extended confrontation with a junkie prostitute and her pimp, after the junkie's brother dies from a drug overdose resulting from serving as a "drug mule."