observatory resounded with a series of thundering blows. The stars
seemed to sweep aside as the telescope--which had been undamped--swung
round and away from the slit in the roof.

"Great Scott!" cried Woodhouse. "What's this?"

Some huge vague black shape, with a flapping something like a wing,
seemed to be struggling in the aperture of the roof. In another moment
the slit was clear again, and the luminous haze of the Milky Way shone
warm and bright.

The interior of the roof was perfectly black, and only a scraping
sound marked the whereabouts of the unknown creature.

Woodhouse had scrambled from the seat to his feet. He was trembling
violently and in a perspiration with the suddenness of the occurrence.
Was the thing, whatever it was, inside or out? It was big, whatever
else it might be. Something shot across the skylight, and the
telescope swayed. He started violently and put his arm up. It was
in the observatory, then, with him. It was clinging to the roof,
apparently. What the devil was it? Could it see him?

He stood for perhaps a minute in a state of stupefaction. The beast,
whatever it was, clawed at the interior of the dome, and then
something flapped almost into his face, and he saw the momentary
gleam of starlight on a skin like oiled leather. His water-bottle was
knocked off his little table with a smash.

The sense of some strange bird-creature hovering a few yards from his
face in the darkness was indescribably unpleasant to Woodhouse. As his