The story follows Adam Lawrence, trained and nurtured by MI6, whose career seems set to remain the same. But when an old acquaintance, Kara, a Russian spy, approaches him, and the two have a complicated past, Adam is forced to question everything and everyone in his life. Kara, Adam and his wife Maddy form a triangle: all three are trying to uncover each other's secrets, and find ways to properly navigate politics and diplomacy, while protecting their personal lives and the people they love most.