One morning, Sophia Simeonidis, a former opera singer, discovered an unfamiliar tree in her garden. Beech. Who planted him? And for what? Pierre, Sophia's husband, does not care about these oddities. However, she is alarmed, loses sleep and finally asks her neighbors, three young eccentric historians, to dig a hole under the tree to find out if anything is buried under it... And a few weeks later, Sophia disappeared. Soon they found a burnt corpse. Her corpse? The police are investigating. Neighbors too. They liked Sofia. The sudden appearance of the beech tree now seems even more mysterious...