.
"There is the mark of another woman's foot which I cannot find on the
stair in the hall. This woman walked all round the house; I think she
walked round twice; and then she walked into the garden and through the
trees."

Tarling stared at him.

"Miss Rider came straight from the house on to the road," he said, "and
into Hertford after me."

"There is the mark of a woman who has walked round the house," insisted
Ling Chu, "and, therefore, I think it was a woman whose feet were bare."

"Are there any marks of a man beside us three?"

"I was coming to that," said Ling Chu. "There is a very faint trace of a
man who came early, because the wet footsteps are over his; also he left,
but there is no sign of him on the gravel, only the mark of a
wheel-track."

"That was Milburgh," said Tarling.

"If a foot has not touched the ground," explained Ling Chu, "it would
leave little trace. That is why the woman's foot about the house is so
hard for me, for I cannot find it on the stair. Yet I know it came from
the house because I can see it leading from the door. Come, master, I
will show you."

He led the way down the stairs into the garden, and then for the first
time Whiteside noticed that the Chinaman was bare-footed.

"You haven't mixed your own footmarks up with somebody else's?" he asked
jocularly.

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