The wings of the sphinx

Things are not going well for Inspector Salvo Montalbano. His long-distance relationship with Livia is on the rocks, his age is catching up with him, and he's getting tired of the violence that is part of his job. Then the dead body of a young woman is found. Her identity is at first unknown, but the tattoo of a sphinx moth on her left shoulder links her with three other girls bearing the same mark who have been rescued from the Mafia nightclub circuit by a prominent Catholic charity. The problem is, they can't help Montalbano with his enquiries - as they are all missing ...