In Le Cœur du problème Simon comes home to find a fully-clothed man lying dead in the lounge of his house. Simon's (doctor) partner Diane is having a bath, is very casual about the body, and picks up her things and walks out on him, hoping he'll take care of the situation.
Which he does, and in a typically Oster fashion, agonising over every minor detail (such as the ice packs to use initially to prevent the body from smelling too much, etc) until he finally buries it in the kitchen garden. Which is not the end but only the start of Simon's problems.
Simon reports Diane's disappearance to Henri, a cop who very soon retires but takes far too much interest in Simon's affairs, as he's suspicious about the poor state of Simon's balustrade, seems to have a vague interest in the vegetable garden (where Simon's buried the body), and is aware of the strange simultaneous disappearance of a male doctor.
Henri introduces Simon to his wife Nicole, and the trio are (sort of) getting on so well that Henri invites Simon for a few days' visit to Nicole's sister Raphaëlle's place. Simon, who is now interested in selling his house, is of course anxious about what Henri suspects, and Raphaëlle initially adds to his concerns by wondering why Henri is so interested in Simon, although she tells him not to worry.
Raphaëlle in fact seems to be a kind of fairy godmother, or guardian angel, to Simon. In a surreal, dream-like, drunken party in a partly restored castle in the village, to which Raphaëlle invites Henri, Nicole and Simon, the seriously drunk co-host Cécile Pajol befriends Simon to such an extent that she won't let him leave her. But after, Henri says he's very interested in buying Simon's house.
And then Diane (who has been in London and whom Simon has briefly met there) phones to say she wants to come clean about the (accidental?) killing. Simon doesn't think that that's a good idea. Henri contacts him to say he's no longer interested in the house, and Simon goes to visit Raphaëlle, who after a moment's surprise by his visit says she'll put the coffee on. End of story.
Loose ends? Reader left in the middle of a the story with nowhere to go, or can Simon now relax without any more problems? Who can tell: this is just Christian Oster playing with the reader again.
My other posts on Christian Oster:
Christian Oster: Dans le train
Christian Oster: Une femme de Ménage | Cleaning Woman
Christian Oster: Rouler