They say she lives quite alone, and that her servants come in the morning and leave at night.

Sure they will none of them have courage to pass the threshold when that sign adorns it, and the old hag will have to come forth herself to seek them.

An excellent joke! I will watch the house, and give her a kiss as she comes forth." Whereupon the whole crew burst into shouts of drunken laughter, and made a rush to the door, which stood flush in a grim-looking wall just beneath the shadow of the church of Allhallowes the Less.
Frederick had the paint pot in his hand, and he traced a fine red cross upon the door, all the while making his ribald jests upon the old woman within, he and his companions alike, far too drunk with wine and unholy mirth to have eyes or ears for what was happening close beside them.

They did not hear the sound of an opening window just above them.

They did not see a nightcapped head poked forth, the great frilled cap surrounding a small, wizened, but keenly-courageous face, in which the eyes were glittering like points of fire.
None of them saw this.