(Duct:)
Something slithered.
He paused, listening, but it didn't seem to come again; so he bent his head back to his work, examining the calligraphy through the magnifying glass, studying the shapes of the serifs.
There it was again, dry and dusty, suggestive of scales.
And it was coming from the vent.
For the first time, he wondered what was on the other side.