The light went out. The hidden person paced up and down the room as though imitating the action of some person who had been there before.

One chair moved slightly; then the position of the other was disturbed. Again the invisible being went to the door; then to the table; finally to the window. The shade was carefully raised.

The light, muffled in the palm of a hand, now flashed upon the latch of the window, then went out.

The sash came up noiselessly. A figure, almost invisible, emerged through the window. The sash was lowered, from the outside, and a form dropped into the alley below.

The tiny light ran along the cement. There were no footprints there, but at one edge, where the cement ended, there was a slight mark on the ground, as though the toe of a shoe had overstepped the edge.

A hand, holding a tiny steel tape measure, spread above the spot, and made careful measurements. The single hand worked alone, handling the tape deftly.

The flashlight’s gleam was reflected by a large bluish gem that shone from the third finger. It was a girasol, or fire opal, that cast a strange, red reflection.

Then the light was gone. There was no sound; no movement in the darkness. A few seconds later, a window opened from a house in back, and the light from a room fell on the spot where the hand had been. No one was there.

* * *

The door of the city morgue was heavy, and old-fashioned. Tonight, a half hour after the episode at the rooming house, the huge portal opened noiselessly, and closed without even the slightest clang.