While her children force her to contact the potential fathers of her child, Morgane is called to new investigations: Antoine Broussin, 85 years old, author of crime novels, is found dead in a secret room of his house.

In the Cathy Barriot death case, Morgane notices that bath balls that have fallen on the floor tend to be evenly distributed. It looks as if someone had put them there on purpose. Which means it must not be an accident, but murder.