The Scheleur rises somewhere in the jungle's interior—the Neka claim to know its source but don't share that information—and flows southwest before curving west to empty into the sea south of Urok's main landmass. For most of its length it's a typical jungle river: brown water, overhanging vegetation, things with teeth lurking beneath the surface.
But where it passes within a few miles of the Firespine, the Scheleur changes character. The water warms. The color shifts from brown to a faintly reddish tinge (mineral content from the heated groundwater, probably, though the Neka have other explanations). The species living in this stretch are found nowhere else—adapted to temperatures that would kill their relatives downstream.
Yanayazi claims stewardship of the warm stretch, but the river is technically accessible to all Neka. Fishing rights are governed by informal traditions rather than strict law, which occasionally causes friction when a Kanamazi hunting party takes fish that Yanayazi considers theirs. These disputes rarely escalate beyond angry words—the confederacy has larger concerns—but they're a persistent minor irritation.
The river is navigable by small craft from Yanayazi to the coast. Larger vessels can't handle the shifting channels and submerged debris. Foreign cartographers named it the Scheleur; the Neka simply call it Yolu-Mazi, "fire's vein."