As she came forward her movements were so stealthy that her footsteps made no sound.

Her dark shadow, moving ahead of her across the floor, was not more silent than she.

An undefined desire to make a noise, to give the alarm, seized me.
Half-way across the room she stopped to listen, and looked round, startled herself, I think, by the silence.

She could not see her sister, whose figure was blurred by the outlines of the curtain; and no doubt she was puzzled to think what had become of her.

The suspense which I felt, but did not understand, was so great that at last I moved, and the bed creaked.
In a moment her face was turned our way, and she glided forwards, her features still hidden by the hood of her cloak.