NCIS Season 8 Episode 8 : Enemies Foreign
The team is designated to protect Eli David (Mossad Director & Ziva's father) during a NCIS conference. They must deal with three Palestinian terrorists trying to kill him. The episode ends on a cliffhanger when, after an attack by the terrorists at the conference apparently fails, Vance and David go to a safe house. Gibbs cannot reach them on the radio and Officer Hadar is shown to be lying dead at the safe house.