Set in London in the '70s, our two protagonists, Max and Natalie, meet under unusual circumstances. He recruits her, trains her, falls in love with her and sends her almost to her death on a disastrous mission in East Berlin. In an attempt to win her back, Max leaves MI5 and promises her a more settled future in his newly formed detective agency, but they are soon drawn back into the world of spying and come again under the control of Max's overbearing boss, Soames. This time, they are thrown into the turmoil of Northern Ireland, where the IRA has kidnapped a millionaire's daughter in an attempt to revive the Troubles. Again, their skills as agents are tested, as is their commitment to each other. Will their relationship survive this time? Will they finally escape from MI5? Will Max and Natalie finally be able to bury their ghosts?