Le Guide, France's premier gastronomic guide, is failing to whet the appetite of its audience in America. Bribed by the Director with offers of some time off, Monsieur Pamplemousse agrees to flex his literary muscles in a bid to address the problem by writing a play. The result is the ex-detective's directorial debut, complete with walk-on part for faithful bloodhound Pommes Frites. Everything rests on their special guest, Jay Corby, the acclaimed American food-critic, whose good opinion could change their transatlantic fortunes. But disaster strikes on opening night when a manoeuvre with a trapdoor causes Corby to storm out in a rage. Monsieur Pamplemousse must find him before he ruins everything for Le Guide. Once again he can rely on star sniffer dog Pommes Frites, who is hot on the trail of their only lead: a flimsy undergarment belonging to an exotic dancer they came across in a state of undress before the start of the show.