To the students at the Great Academy, it was simply the Nabla. They used it to calculate the flow of heat through iron, the pull of gravity between cold moons, and the swell of ocean tides. It was a tool of measurement, a tidy operator in their leather-bound textbooks.
At the very base of the Sunken Valley sat the Singularity Stone, an artifact from a forgotten civilization that understood the math of the universe too well.
"Because nothing in this universe likes to stay where it is," Elian had answered, his voice raspy from the valley’s sulfurous wind. "Everything is sliding. Heat flees to the cold. High pressure screams toward the void. Rivers butcher mountains just to find a lower place to rest."