Rachel Thyssen, McGill's ex-girlfriend, spots her father Harry, who supposedly drowned years ago. Harry was McGill's boss in American intelligence, from which McGill was forced to resign, scapegoated when LaFarbe, a scientist under observation, defected to Russia. Harry died, it was thought, before he could clear McGill's name. In reality, he is now undercover, relaying secrets back from LaFarbe, a double agent working for the Americans, back to the West. McGill needs his help, but he is not the only one on Harry's trail - the Russians are also taking an interest in him.