The wildfire is visible from space, an ever-burning semicircle that connects the planet’s poles. East of this phosphorescent meridian, the world remains violet with life; to the west, however, there is nothing to be seen but smoke and desert, a landscape ruled by worms. The flames take several earth-months to complete a single rotation, allowing just enough time for the fields to regrow. Satellites orbiting its equator can see the entire gradient of life and death in a single rotation, from ashes to fertility to ashes once more.
The first hooves of what has come to be known as the Forever Stampede can be heard just a few miles east of the wall of fire. The animals of this world spend their lives in flight, thundering and fluttering and slithering ever eastward. They graze in brief bursts when possible, and those who have not yet evolved the ability to live without sleep ride on each other’s backs. Long trunks and tendrils drag behind their bodies, slurping up water, mosses, and underbrush. There are predators in such a place as well, powerful creatures with many-toothed limbs which allow them to drag or carry their kills with them as they run.
An expeditionary team of astrozoologists made an extraordinary discovery while observing the stampede via gyrocopter: a small tribe of nude humans running alongside a pack of tumbledeer. They were found to be the surviving crew of a freighter that had crash-landed on its surface almost a decade prior, forced to adapt to the ever-moving biosphere. They had no supplies left from their days as star runners, for whatever they once carried with them had long since been trampled, burned, or lost, including their distress beacon. They had managed to adapt and survive against unfathomable odds, hunting as a pack and befriending some of the larger beasts to sleep upon their backs at night.
Even though the survivors’ descriptions of this experience were hellish, many humans have since voluntarily elected to run with the Forever Stampede, and many more train and take supplements to pursue this goal. Some choose it as a personal challenge of fitness and sport, some do so because they have nothing left to lose, and others still are seeking enlightenment through the sacrifice of all personal possessions. The physical endurance required is extraordinary, but the mental endurance perhaps more so. For most of the rescued crew of that ill-fated vessel, the flames continue to pursue them in dreams, and to remain still for more than a few hours is to give in to madness.