Spooks, or MI-5, is a show about British spies that work in counter-terrorism. (all airdates are UK airdates). The spies are collectively known as Spooks because of the shadowy nature of their existence. The Spooks use many different covers, and rarely get to use their real identities out in the open. These secret agents are tasked with the mission of protecting the national security of the UK. Note from the official website: Each episode is shown first on Fridays, 9.00pm, BBC THREE. And then later shown at 9pm on Wednesdays on BBC One (somewhat confusing, no?). Source: http://www.bbc.co.uk/programmes/b006mf4b/episodes/upcoming
