The First NCIS Mole Hunt was an operation that occurred in September 2008 and which saw NCIS Director Leon Vance secretly informing NCIS Special Agent Leroy Jethro Gibbs that one member of Gibbs's new team was suspected to be a traitor and also responsible for selling highly classified information. After the death of NCIS Special Agent Brent Langer who was believed to be the mole, the operation ceased to exist although it was later revealed that NCIS Special Agent Michelle Lee was the true mole and that she had killed Langer to preserve her cover.