Topa, a growing planet in the Leire System, is the home of a group of humans who descend from American Indian tribes on Earth. The planet has large natural deposits of Trillium, and because of those stores, the Colonial Confederacy annexed the world in early 3199, hoping to set up colonies of their own and take advantage of the rare and useful minerals.

Santa Fe Science, a scientific company based on Atlanta Gemini Station above Lincoln, set up a series of facilities on the planet, all within a 50 mile radius of the initial colonial landing site, now known as Topa City. Santa Fe Science has run many scientific tests using Trillium on the planet, working to use the mineral in the most effective ways for the fleets of the Confederacy.