Ricardo Somocurcio is in love with a bad girl. He loves her as a teenager in Lima in 1950, and next in Paris, where she appears as the enchanting Comrade Arlette. In Llosa's beguiling new novel, a riff on Madame Bovary, the strange bedfellows of good and bad turn out not to be what they appear.  (PRU81, $14.00)