Locus is the largest cluster habitat ever formed. It is still growing, with over one million inhabitants in the habitat proper and another million in the nearby suburbs of scum barges and small asteroid stations. Locus is located in Cassandra’s Reach, one of the denser regions in the L5 Trojans. The habitat is positioned at the center of mass around which the two asteroids making up the binary object Patroclus orbit one another. Both Patroclus asteroids are themselves inhabited and hold defense installations, mines, and refineries.

The design of Locus is very similar to the much smaller Lot 49, but Locus is eleven kilometers in diameter and somewhat irregular in shape, as growth along some spars is faster than others. A quarter of its total volume is cut out in a roughly conical shape all the way to the Amoeba, an immense, softly glowing sculpture at the center of the habitat. Some differences from smaller Trojan clusters are dictated by Locus’s size. The immense structural spars radiating from the habitat’s center are hollow, with arterial floatways and elevator-trams running inside of them. Lesser spars run between the arterial spars, providing more mooring points for modules. Adjacent to each arterial spar are wide “roads” leading to the edge of the habitat so that modules can maneuver out if the owners decide to leave.

Beneath the shimmering mesh stretched over the geodesic frame to keep out micro-asteroids, tens of thousands of small ships and habitat modules moored along the spars pulse with an ever-changing array of lights. Habitat modules and large ships are asked to stay out of the conical empty space. This space teems with small craft and people on thrustpacks or voidscooters as they cross the habitat, play zero-g games, or visit the free- oating spimes and sculptures that dot the area. The Amoeba, which periodically changes color and shape based on its resident AI’s programming (often it looks like some sort of animal), serves as a central reference point for navigation. When someone gives the address for a module, it is as a point on a spherical coordinate system with the Amoeba at its center. Large ships and shuttles dock on the outer surface of the habitat, at the terminal points of the arterial spars.

Locus was founded by a joint anarchist-argonaut venture and was the first major stronghold for the autonomist factions. Unlike Extropia, which has the tacit blessing of the Planetary Consortium and encourages the presence of security and insurance companies, Locus runs on a pure reputation economy. Security, maintenance, expansion, and defense of the habitat are all performed by volunteers. Inhabitants interested in security monitor incoming ships and operate crowdsourcing systems that dispatch volunteers to perform WMD scans on new arrivals. Ships that won’t submit to a scan are asked to leave. If they don’t, anyone who’s designed a cool new weapons system recently is welcome to take a shot.

Locus is a focal point in the cold war between the hypercorp-aligned inner system powers and a loose coalition of outer system interests. While saboteurs from the Planetary Consortium and other hostile entities can and do occasionally cause trouble on Locus, the hypercorps are currently unwilling to attempt a direct military attack on the habitat. The first time they tried, the Planetary Consortium and the Martian city-state of Valles-New Shanghai sent a small expeditionary fleet. The interlopers were caught completely off-guard by a erce and well-coordinated defense. Six months later, they sent a much larger fleet. Help arrived from elsewhere in the Trojans and Greeks and from Titan, whose citizens took a dim view of any Planetary Consortium expansion beyond the belt. The Titanians now maintain a permanent base near Locus. Rumor has it they agreed to a mutual defense pact with one of Locus’s citizens, possibly the famous programmer-armsman Teilhard Liu.