Dinin’s lizard trotted along in an easy but swift gait, floating over the broken floor, up the walls, and even across the long tunnel’s ceiling. Subterranean lizards, with their sticky and soft three-toed feet, were preferred mounts for just this ability to scale stone as easily as a spider. Crossing hard ground left no damning tracks in the lighted surface world, but nearly all of the creatures of the Underdark possessed infravision, the ability to see in the infrared spectrum. Foot-falls left heat residue that could easily be tracked if they followed a predictable course along a corridor’s floor