S1, E2: The Metropolitan Police launches the UK's biggest ever manhunt after a botched suicide bomb attack; racing against time to stop the would-be bombers before they strike again; a major surveillance operation at a South London address.

S1, E2: The Metropolitan Police launches the UK's biggest ever manhunt after a botched suicide bomb attack; racing against time to stop the would-be bombers before they strike again; a major surveillance operation at a South London address.