The episode begins with the sound of Sirens and a Dog Barking. Christine (Smith) arrives home to her flat with Adam (Riley), whom she has just met at a New Year's party. Thirteen months later, it is Valentine's Day and Christine chats with her flatmate Fung (Liu) at home. Christine is dating Adam, but receives a card from her first boyfriend, whom she has not seen since childhood. On Mother's Day, Christine's mother Marion (Dotrice) visits. Marion reveals that Christine's first boyfriend died when he was 16, which Christine had forgotten. Marion urges Christine to marry Adam; Christine's father Ernie (Copley) has Alzheimer's disease and is deteriorating. The following year, Adam moves in with Christine at Easter. Christine begins to prepare a surprise for him, but is disturbed when an egg smashes on a nearby wall. In her kitchen, which is covered with Egg Shells on the Floor, she is approached by an unknown man, the Stranger (Shearsmith) who says "I'm sorry".
