The opera singer Sophia Siméonidis wakes up one morning to discover that a tree has appeared overnight in the garden of her Paris house. Intrigued and unnerved, she turns to her neighbours: Vandoosler, an ex-cop, and three impecunious historians, Mathias, Marc and Lucien - the three evangelists. They agree to dig around the tree and see if something has been buried there. They find nothing but soil.

A few weeks later, Sophia disappears and her body is found burned to ashes in a car. Who killed the opera singer? Her husband, her ex-lover, her best friend, her niece? They all seem to have a motive.

Vandoosler and the three evangelists set out to find the truth.