Castle (2009): Season 5, Episode 23

5 - 23: The Human Factor

When Homeland Security inexplicably seals the crime scene of a car bombing, Castle and Beckett find themselves with two mysteries on their hands: who murdered the victim, a government whistleblower, and why are federal agents trying to take over the case? The plot thickens when they discover that the victim wasn't killed by a car bomb but by a missile from a military drone.