Sister Thérèse is told by Father Vernier that she is to put a stop to her sleuthing activities. However, when a man falls from a building and lands on the roof of her van, can she reasonably be expected to mind her own business? All the more so as the accident turns out to be a murder! The victim, a transport company manager, had managed to make himself no shortage of enemies, particularly by marrying Viviane, the company owner. The main suspects include Viviane's son, Dimitri, who hated his new father-in-law