Book excerpt: "Elvi, which one is your mum?" "They're both my mums." "But which one's your real mum?" When Nicholas wants to know which of Elvi's two mums is her real mum, she gives him lots of clues. Her real mum is a circus performer, and a pirate, and she even teaches spiders the art of web. But Nicholas still can't work it out! Luckily, Elvi knows just how to explain it to her friend...