The Pit-Prop Syndicate

Seymour Merriman, the junior partner in a firm of London wine merchants, is traveling by motorcycle from Avignon to Bordeaux when his vacation grinds to a sudden halt. Out of gas, he follows a passing truck to a mill where an English firm manufactures pit-prop supports for coal mines. He's given two liters of gas and is about to depart when he notices something peculiar — the truck he followed was marked No. 4, but now it's labelled No. 3. His curiosity piqued, Seymour makes some inquiries ...