The story begins on the 75th birthday of identical twin sisters, Dora and Nora Chance. By what Dora, who is also the narrator of the story, describes as a bizarre coincidence, it is also the 100th birthday of their natural father, Melchior Hazard, and his fraternal twin brother, Peregrine Hazard, who is believed to be dead. The date is also Shakespeare's supposed birthday – 23 April.[4]
Dora and Nora's birthday gets off to a dramatic start when their half-brother, Tristram Hazard, who believes himself to be the nephew of the twins, arrives on their doorstep. He announces that Tiffany – his partner, and the goddaughter of the twins – is missing. Dora and Nora soon discover that Tiffany is pregnant with Tristram's baby, but he is unwilling to take on the responsibility. Once this bombshell has been dropped, it emerges that a body has been found and it is believed to be Tiffany's.
Most of the novel consists of Dora's memories. As well as providing the backstory of her natural father, Melchior Hazard, her legal father, Peregrine Hazard, and her guardian, Grandma Chance, Dora describes key events of her life. As Melchior becomes a renowned Shakespearean theatre actor in the 1920s, he refuses to acknowledge his daughters, who are publicly and legally believed to be the daughters of Peregrine instead. Dora is deeply hurt by Melchior's rejection, contrasting the loving nature of Peregrine, who becomes the twins' father figure. She recalls her early theatre performances and her first sexual experience, in which she impersonates Nora and sleeps with her unknowing lover. Melchior marries Lady Atalanta Lynde, who Dora calls "Lady A", and has two legitimate twin daughters, Saskia and Imogen. In the 1930s, he goes to Hollywood and produces a film version of A Midsummer Night's Dream in which Dora and Nora play Peaseblossom and Mustardseed. The production ends in disaster as Melchior leaves his first wife to elope with the wife of the film's producer, who plays the Titania to his Oberon in the film.
After the Second World War, during which Grandma Chance is killed in the Blitz, Dora and Nora attend the 21st birthday party of Saskia and Imogen. Melchior announces, to Saskia and Imogen's fury, a third marriage to the best friend of Saskia, who is playing Cordelia in his King Lear. The announcement sparks a family argument in which Peregrine disappears, never to be seen again. The same night, Lady A falls down a flight of stairs and becomes confined to a wheelchair for the rest of her life; she moves in with Dora and Nora. It is implied Saskia and Imogen may have pushed her down the stairs in their rage. Melchior has two more twins, Tristram and Gareth. Saskia, in an act of vengeance, enters into an incestual sexual relationship with her half-brother Tristram. Gareth, meanwhile, becomes a priest and vanishes.
Dora, Nora and Lady A attend Melchior's 100th birthday party, where most of the novel's expansive cast of characters are in attendance. Melchior acknowledges Dora and Nora are his children for the first time in their lives. Peregrine makes a dramatic entrance accompanied by Tiffany, revealing both are still alive, and Lady A reveals that Peregrine is the true father of Saskia and Imogen. While Melchior and Nora share a dance together, Dora has sex with her paternal uncle Peregrine upstairs. She asks Peregrine if he is her father too; Peregrine strongly denies it, but suggests Grandma Chance may have been Dora and Nora's true mother.
The novel ends with Dora and Nora being presented with the twin babies of the missing son Gareth to look after – a gift from Peregrine. They realise that they "can't afford" to die until they've seen their children grow up. The final line of the story is a message constantly conveyed throughout the novel: "What a joy it is to dance and sing!"
