Spies, assassins, surveillance, and sudden death are business as usual for the Special Branch of London’s Metropolitan Police. A classic British drama from the 1970s, this gritty police procedural focuses on the veteran cops and brash newcomers dedicated to stopping terrorism and countering espionage in the nation’s capital.
The officers of the Special Branch mount a dawn raid on the homes of the members of a suspected spy ring.
Cowley suicides shortly after an unproductive round of questioning by Eden in gaol, which leads to an embarrassing public coroner's inquest. Jordon investigates a scientist being vetted for a sensitive position and all agree he's too far left for further consideration, yet he still succeeds.
A small boat arrives at a beach in Kent where illegal aliens are unloaded, but the police bag the smugglers and all bar one of the Pakistanis, now quite ill, who seeks refuge with an immigrant rights activist.
The son of a trusted officer of the special branch has become radicalised while away at university, trying to join a gang of riot-minded militant socialist students. This threatens to break up his family, and his father's position.
A girl lands at Heathrow from Rhodesia, but owing to Britian's break of diplomatic relations, she has no valid passport. A young officer is supposed to mind her until she can be sent back, but takes her for a tour instead.
A girl being held for giving official secret documents to the Russians faces a long gaol term, but an exchange offer for a Briton arrested in Moscow is offered. The officers suspect she's far more than she seems to be.
Jordan's methods cause friction in an overseas British Embassy when he goes to investigate the theft of ten thousand pounds.