Father Clemence, a man burned by his faith, has taken in search of retribution. Along the way, he is joined by Maria, a hitch hiking punk, who is fleeing her home in Mexico City. Together, the odd couple embark on a roller coaster of adventure that is at times both harrowing and heart warming.

Tense drama series about the different challenges faced by the British Security Service as they work against the clock to safeguard the nation. The title is a popular colloquialism for spies, and the series follows the work of a group of MI5 officers based at the service's Thames House headquarters, in a highly secure suite of offices known as The Grid.