Sibylla, a single mother from a long line of frustrated talents, has unusual ideas about child rearing. Yo Yo Ma started piano at the age of two; her son starts at three. J.S. Mill learned Greek at three; Ludo starts at four, reading Homer as they travel round and round the Circle Line. A fatherless boy needs male role models; so she plays the film of Seven Samurai as a running backdrop to his childhood. While Sibylla types out back copies of Carpworld to pay the rent, Ludo, aged five, moves on the Hebrew, Arabic and Japanese, aerodynamics and edible insects of the world - they might come in handy, if he can just persuade his mother he's mature enough to know his father's name. He is bound for knowledge of a less manageable sort, not least about his mother's past. And at the heart of the book is the boy's changing relationship with Sibylla - contradictory, touching and tender.