Undercover CIA agent Martian is ordered to return to London. When the woman he left behind suddenly reappears, their love is rekindled, entangling them in a deadly game of intrigue and international espionage.

Homeless and on the run from a military court martial, a damaged ex-special forces soldier navigating London's criminal underworld seizes an opportunity to assume another man's identity, transforming into an avenging angel in the process.