They died heart to heart, chest to chest. Detective Kovelant, haunted by the fiery death of two women, investigates why Chloe Bisset, mother and wife, swerved last-second into oncoming traffic. What drove her to this impulse? L'appel du vide, he soon discovers, is both an explanation and a non-explanation. The phrase translates to "the call of the void," which doesn't surprise him. The French often have ways of expressing the unexplainable. Most never answer the call, but only briefly contemplate what could happen. Kovelant tracks Chloe's acts through her final days-a series of experiments in spontaneity that end with her crossing one final line on the asphalt to end two lives. Clues scribed with fridge magnets, etched into silver rings, scribbled on sticky notes, and painted on the smoke-stained walls of a derelict building, reveal a woman tormented by a growing need. Each revelation drives him closer to the grief that pins him to his own dark truth. Parents should never outlive their children.