Ricardo Somocurcio is in love with a bad girl. He loves her as a teenager known as 'Lily' in Llama in 1950, when she arrives one summer out of the blue, claiming to be from Chile but vanishing the moment her claim is exposed as fiction. He loves her next in Paris, where she appears as the enchanting 'Comrade Arlette', an activist en route to Cuba, and becomes his lover, albeit an icy, remote one who denies knowing anything about the Lily of years gone by. Whoever the bad girl turns up as - whether it's Madame Robert Arnoux, the wife of a high-ranking UNESCO official, or Kuriko, the mistress of a sinister Japanese businessman - and however poorly she treats him, Ricardo is doomed to worship her.

Gifted liar and irresistible, maddening muse - does Ricardo ever know who she really is? The answer is an unclear as what has become of Ricardo himself, a lifelong expatriate shadowed by the sense that he is only ever drifting.

Mario Vargas Llosa's beguiling new novel The Bad Girl, tries to differentiate between the strange bedfellows of good and bad, proving that either can turn out not what they appear to be.