An unusal death

One night, when Luc Bucher organizes a party for his thirty-five years of existence, he is found dead in his bed. In fact, he had a stomachache before his death. The detective Julien Deloi will have to find the culprit among the ten guests. Apperently, it seems to be an accidental death, but this death proves to be a murder. The guests seem all silent, wise and reserved, but there's maybe something they are keeping quiet about.