Even as he looked, two shadows darkened the white surface--the shadows of a man and a woman.

Evidently they had come between the lamp and the window, and so, quite unknowingly, revealed their actions to the watcher.

Curious to see the end of this shadow pantomime, Lucian stood still and looked intently at the window.
The two figures seemed to be arguing, for their heads nodded violently and their arms waved constantly.

They retreated out of the sphere of light, and again came into it, still continuing their furious gestures.
Unexpectedly the male shadow seized the female by the throat and swung her like a feather to and fro.

The struggling figures reeled out of the radiance and Lucian heard a faint cry.
Thinking that something was wrong, he rushed up the steps and rang the bell violently.