Aimee's childhood friend, Laure, is a policewoman. Her partner, Jacques, has set up a meeting in Montmartre with an informer. When Laure goes along as backup, Jacques is lured to a rooftop, where he is shot to death. Laure's gun has been fired, gunpowder residue is on her hands, and she is charged with her partner's murder.

The police close ranks against the alleged cop killer. Aimee is determined to clear Laure's name. In doing so, she encounters separatist terrorists, Montmartre prostitutes, a surrealist painter's stepdaughter, and a crooked Corsican bar owner, and learns of "Big Ears"-the French "ear in the sky" that records telephonic and electronic communications for the security services. Identifying Jacques' murderer brings her closer to solving her own father's death, which still haunts her. She cannot rest until she finds out who was responsible.