In the 1970s, British intelligence went mad. Some MI5 officers spread the story that Harold Wilson was a KGB agent. Others bugged Downing Street. It was even believed that the endless industrial disruption of those days was a Soviet plot. Promising territory for a spy thriller. But Legacy (28 November) was a disappointment. It caught the look of the time. But the storyline – a KGB attempt to sabotage nuclear power stations – was implausible on a number of levels.Paula Milne’s script (based on Alan Judd’s novel) was a tale of a young intelligence officer (Charlie Cox as Charles Thoroughgood) told to “turn” an old university chum, now in the Soviet Embassy and, most likely, a KGB man (Andrew Scott as Viktor Koslov). Koslov was an easy nut to crack, not le