Tom Marcus was recruited by MI5 in the wake of the 7/7 attacks on London. After five years spent undercover as part of a covert British Army Special Operations unit, he offered the Security Service the edge they so desperately needed. Following months of intensive training, Marcus was thrown into a world of relentless, unimaginable pressure; a never-ending struggle to prevent terrorist atrocities on our city streets, foil devastating strikes against the nation's infrastructure, and keep our country's secrets safe from foreign spies. In this explosive first-hand account, he lifts the lid on the war being waged by MI5 to keep us safe in our towns and cities.