"And if she lies, the impression of the heel will give her away," the coroner suggested.
Robinson grinned.
"You'd make a rotten detective, Coroner. Women's heels are cut to a pattern. There are thousands of shoes
whose heels would fit this impression. We need the sole for identification, and that she hasn't left us. But she's
done one favour. She's advertised herself as a woman, and there are just three women in the house. One of
those committed this serious offence, and the inference is obvious."
Before Bobby could protest, the doctor broke in with his throaty rumble: "One of those, or the woman who
cried about the house."
Bobby started. The memory of that eerie grief was still uncomfortable in his brain. Could there have been
actually a woman at the stagnant lake that afternoon and close to the house to-night--some mysterious friend
who assumed grave risks in his service? He recognized Robinson's logic. Unless there were something in that
far-fetched theory, Katherine faced a situation nearly as serious as his own. Robinson straightened. At the
same moment the scraping of a window reached them. Bobby glanced at the newer wing. Katherine leaned
from her window. The coincidence disturbed him. In Robinson's mind, he knew, her anxiety would assume a
colour of guilt. Her voice, moreover, was too uncertain, too full of misgivings:
"What is going on down there? There have been no--no more tragedies?"
"Would you mind joining us for a moment?" Robinson asked.
She drew back. The curtain fell over her lighted window. The darkness of the court was disturbed again only
by the limited radiance of the flashlight. She came hurriedly from the front door.
"I saw you gathered here. I heard you talking. I wondered."
"You knew there were footprints in this court," Robinson said harshly, "that Howells connected them with the
murderer of your uncle."
"Yes," she answered simply.
"Why then," he asked, "did you attempt to obliterate them?"
She laughed.
"What do you mean? I didn't. I haven't been out of the house since just after luncheon."
"Can you prove that?"
"It needs no proof. I tell you so."
The flashlight exposed the ugly confidence of Robinson's smile.
"I am sorry to suggest the need of corroboration."
"You doubt my word?" she flashed.
"A woman," he answered, "has obliterated valuable testimony, I shall make it my business to punish her.