At eleven o'clock a comparative quiet had come upon Half-Moon Street.
The sound of the traffic had gradually subsided, until it seemed to
him that the house stood, not in the busy West End of London, but
isolated, apart from its neighbours; it seemed to him an abode, marked
out and separated from the other abodes of man, a house enveloped in
an impalpable cloud, a cloud of evil, summoned up and directed by the
wizard hand of Antony Ferrara, son of the Witch-Queen.

Although Myra pretended to read, and Dr. Cairn, from his fixed
expression, might have been supposed to be pre-occupied, in point of
fact they were all waiting, with nerves at highest tension, for the
opening of the attack. In what form it would come--whether it would be
vague moanings and tappings upon the windows, such as they had already
experienced, whether it would be a phantasmal storm, a clap of
phenomenal thunder--they could not conjecture, if the enemy would
attack suddenly, or if his menace would grow, threatening from afar
off, and then gradually penetrating into the heart of the garrison.

It came, then, suddenly and dramatically.

Dropping her book, Myra uttered a piercing scream, and with eyes
glaring madly, fell forward on the carpet, unconscious!

Robert Cairn leapt to his feet with clenched fists. His father stood
up so rapidly as to overset his chair, which fell crashingly upon the
floor.

Together they turned and looked in the direction in which the girl had
been looking. They fixed their eyes upon the drapery of the library
window--which was drawn together. The whole window was luminous as
though a bright light shone outside, but luminous, as though that
light were the light of some unholy fire!

Involuntarily they both stepped back, and Robert Cairn clutched his
father's arm convulsively.

The curtains seemed to be rendered transparent, as if some powerful
ray were directed upon them; the window appeared through them as a
rectangular blue patch. Only two lamps were burning in the library,
that in the corner by which Myra had been reading, and the green
shaded lamp upon the table. The best end of the room by the window,
then, was in shadow, against which this unnatural light shone
brilliantly.

"My God!" whispered Robert Cairn--"that's Half-Moon Street--outside.
There can be no light--"

He broke off, for now he perceived the Thing which had occasioned the
girl's scream of horror.

In the middle of the rectangular patch of