 Cal Blair hates space travel, and he's not very keen on surgery either, which is why his relationship with Tinker Elliot, a spacefaring surgeon, has never blossomed into marriage.When the long-lost electronic key to Hellion Murdoch's hidden treasure finds its way into Blair's hands, though, he winds up deeply involved in both.Cal, a cryptographer, uses his skills to decipher the key, build a device that will allow him to use it to find Murdoch's treasure, and travels to Venus to locate it.