A classic Golden Age locked-room mystery in which the discovery of a body turns a cross-country train journey into a hunt for a killer. Indroduction by Otto Penzler.

The luxurious Transcontinental Express, a locomotive journeying coast-to-coast across the United States, is the height of 1930s technology and sophistication. Alongside carriages for dining, drinking and dancing, there’s even a swimming pool car – in which the corpse of a banker is found floating facedown just one day into the journey.

With nowhere to hide, any passenger could be next. It's up to the clever Dr Pons – with his sharp wit and knack for impossible puzzles – to get to the bottom of the case, before it is too late.