SJAMBAK by Jack Vance was originally published in the July 1953 issue of IF WORLDS OF SCIENCE FICTION. What I have here is a chapbook published by WILD SIDE PRESS.

KNOW YOUR UNIVERSE! is a science TV series that has two hundred million screens turned on for each episode, an estimated five hundred million participants. An interactive show, the producers are worried that the shows are beginning to be boring and looking for something to juice them up. They hear the tale of the Horseman in Space, a figure that supposedly rises up to greet spaceships coming into orbit around the planet Sirgamesk, without spacesuit. And the planet has no horses. Settled in the past by Javanese, Arabs, and Malay, it’s an airless world with it’s people living in the valleys, airtight roofs built over them. Travel between the valleys is by train completely enclosed. There are vast ruins, unexplored, of the original inhabitants when there was an atmosphere.

Wilbur Murphy is sent there with camera people to investigate, not really believing the Horseman tale, but hoping for footage. On his way to visit the Sultan of Singhalut, the particular valley of the landing, Wilbur sees a naked man in a cage. A Sjambak, a criminal, this particular one had broke the seal on a train, killing all the unprepared to rob them. No one wants to speak of these people, but Wilbur learns they live on the surface, surviving with their oxygen stills.

But Wilbur has stepped into something more than a superstition. Singhalut is overcrowded, fifteen hundred to a square mile. The Sultan wants to expand, opening new valleys for colonization. His son, the Prince, thinks it cost too much. Why pay the cost of building airtight roofs when there are already working valleys?

Interesting story. It is available at Project Gutenberg, but this slim edition is only $2.99. It has a partial bibliography of Vance’s work and a couple of pages about the author.