When Monsieur Pamplemousse is summoned into the head office of Le Guide by the director, Henri Leclercq, he is unaware of the chaos that is about to erupt. Accompanied by his faithful bloodhound, Pommes Frites, Pamplemousse attempts to solve Leclercq's plaintive conundrums - all of which relate back to his mobster uncle-in-law.The crime-solving duo gallivant around Paris and become tangled up in seemingly arbitrary problems; a letter about a juicy steak horrifyingly turned into a brisket; a dead restaurant owner; a giant truffle delivered by post and the imminent arrival of the vivacious Caterina, the mobster's niece.With all these obstacles at hand, Pamplemousse attempts to unravel each dilemma but it quickly proves impossible as they overlap and tangle at every turn. As he battles with this confounding case, it becomes apparent that these events are much more sinister and inextricably linked than first thought ...