The post-birthday world

American children's book illustrator Irina McGovern enjoys a secure, settled life in London with her smart, loyal, disciplined partner, Lawrence—until the night she finds herself inexplicably drawn to kissing another man, a passionate, extravagant, top-ranked snooker player. Two competing alternate futures hinge on this single kiss, as Irina's decision—to surrender to temptation or to preserve her seemingly safe partnership with Lawrence—will have momentous consequences for her career, her friendships and familial relationships, and the texture of her daily life.