The Bajorans believe the alien species that reside in the wormhole near their planet are Prophets, worshipping them as gods and referring to the wormhole as the "Celestial Temple". Bajoran legend tells that millennia ago, the Prophets expelled another race from the wormhole, the Pah-wraiths, imprisoning them forever in the Fire Caves on Bajor. However, legend tells of three red Orbs which are said to hold the key to the Pah-wraiths' resurrection and return to the Temple, although none of these Orbs have ever been located. Or so it is thought. The game is loosely based on a trilogy of novels by Judith and Garfield Reeves-Stevens called Millennium: The Fall of Terok Nor, The War of the Prophets, and Inferno. The setting is the Deep Space Nine space station featured in the American science fiction television series Star Trek: Deep Space Nine.