From the publishers blurb:
Saturn. Well known for the weird magnetic energies of its core, which attract even non-ferrous metals, and which pulled many a would-be Crawljammer to his doom in the early days of space exploration. Saturn. Legendary home of fierce Ape-Men and even fiercer giant worms, which devolved from a great civilization that once worshipped the vast demon-god Tsathoggua before the first great reptiles appeared to dominate long aeons upon the Earth.
It is said that the collapse of that civilization caused the weird energies of Saturn’s magnetic core. Many, but not all, of that demon-haunted culture’s works were drawn into the planet’s crust, there to be crushed and consumed. Even so, there is a flux to that strange magnetic attraction. Once in several thousand years, the magnetic forces wane for a period, and ships may safely approach or land upon Saturn.
The technomancer Satrampa, who has long made her cold dwelling upon the frozen ocean-moon Tethys, has predicted that such a time is near, and seeks adventurers willing to brave the ringed world’s dangers. There they must locate the Vault of Zin the Meticulous. She will pay a man’s weight in gold for the black onyx ring long-dead Zin once wore upon his right hand. Failing that, she will pay the same weight in silver for proof that the Idol of Tsathoggua which one strengthened the ancient sorcerer’s spells is no more.