The ramp was bounded by a guardrail, but it was unnaturally high, reaching to about shoulder-level rather than to the waist. It would still be at least partially effective at keeping me from pitching off the ramp, but it simply didn't match the way most people would have designed it. I leaned over that too-high rail, and looked down. The spiral ramp descended two and a half turns- about twenty meters-into the red-tinged darkness. There was no movement, nothing at all untoward. But that strange, vaguely biological smell kept catching in the back of my throat, triggering all sorts of mental warnings.