Leak (S01E04)

The brutal slaying of two MI5 informants uncovers a troubling leak within a government-operated Missing Person's Scheme. The team is under pressure to identify the source of the corruption and prevent any further murders. Meanwhile, Rachel takes on an undercover role to gather more details about the MI5 cover-up and discovers that a British scientist might have been unjustly incarcerated due to his involvement in the bomb plot.