The 8-episode series, based on an original pitch from Coates, follows two best friends, Judith (Waddingham) and Debbie (Spencer), who know everything about each other—or do they? Unbeknownst to Debbie, Judith has been living a double life as a highly trained assassin. When a hit goes horribly wrong, the pair must go on the run together and work to repair their broken friendship—all while being targeted by a mysterious enemy who wants them dead.！