Ling Chu shook his head.
"I left my shoes outside the door because it is easier for me to work so," he said calmly, slipping his feet into his small shoes.
He led the way to the side of the house, and there pointed out the footprints. They were unmistakably feminine. Where the heel was, was a deep crescent-shaped hole, which recurred at intervals all round the house. Curiously enough, they were to be found in front of almost every window, as though the mysterious visitor had walked over the garden border as if seeking to find an entrance.
"They look more like slippers than shoes to me. They're undoubtedly a woman's," said Whiteside, examining one of the impressions. "What do you think, Tarling?"
Tarling nodded and led the way back to the room.
"What is your theory, Ling Chu?" he asked.
"Somebody came into the house," said the Chinaman, "squeezed through the door below and up the stairs. First that somebody killed and then went to search the house, but could not get through the door."
"That's right," said Whiteside. "You mean the door that shuts off this little wing from the rest of the house. That was locked, was it not, Tarling, when you made the discovery?"
"Yes," said Tarling, "it was locked."
"When they found they could not get into the house," Ling Chu went on, "they tried to get through one of the windows."