Once a celebrated writer, M had his greatest success with a suspense novel based on a real-life disappearance. It told the story of a history teacher who went missing one winter after having a brief affair with a beautiful student of his. The teacher was never found. Upon publication, M's novel was a runaway bestseller, one that marked his international breakthrough.

That was years ago, and now M's career is fading. But not when it comes to his bizarre, seemingly timid neighbor who keeps a close eye on him and his wife. Why?