A Slotted Channel

A narrow steel channel drew my advance near the corner tiles. It was a floor drain, topped with a slotted circular grate. I halted at the rim and planted my boots on the rough concrete. The metal plate bore an oxidized patina, perforated with six parallel vents. Dropping to one knee, I reached down and gripped one of the cold cast slats. I exerted vertical force. It shifted half an inch, rattling against the basin before settling firmly back into its groove. Beneath the slots, absolute darkness and a faint upward draft. An subterranean conduit. I locked my stance beside the aperture, logging its depth. Secure.