When Professor Thibaud, a great bone specialist, asks Joëlle, a simple young girl, to donate her bone marrow in view of a transplant, she agrees without hesitation. Despite the pain and the risks, she only thinks of saving a human life. Just one condition is imposed : the giver is not allowed to meet the transplanted in any case. However it is more than she can take, so Joëlle sifts through the medical network until she meets Arnaud. The more she advances, the more she becomes attached to her transplanted, to the point where she believes that her marrow influences his dreams and desires. Ambiguity will reign throughout this love comedy.