She was about to answer when the curtain in the doorway twitched and an old man came into the room.

One curtain twitched; a woman's face showed for a moment, then vanished.

A moment later the curtains on the barred windows beside the door twitched and then fell back into place.

Suddenly aware that curtains were probably twitching all around, she stepped back.

A shadow passed the window, and the curtain twitched aside.

In the window to our left, as we passed, the curtain twitched slightly, then fell back into place.

The curtains twitched at one of the front windows, and then the door opened.

The curtain in the window on the top floor twitched.

John saw a curtain in one of the front windows twitch, but there was no other sign that they had been observed.

A curtain twitched and a face peered out, only to vanish a moment later.