Used book – Meurtre au beurre de cacahuète, Florence Aubry, Olivier Balez

Victor discovers his neighbor unconscious on her living room carpet. "Coma following an allergic reaction," the doctors diagnose. A simple accident? Victor doubts it. Why would Muriel, who had meticulously chosen her food for twenty years, suddenly eat peanuts? And above all, why would she have left a letter bearing the inscription "If anything happens to me..."?