of the
wanted man to every police station in England. Within twenty-four hours
his description and photograph were in the hands of every chief
constable; and if he had not succeeded in leaving the country--which was
unlikely--during the time between the issue of the warrant and his
leaving Tarling's room in Hertford, his arrest was inevitable.

At five o'clock that afternoon came a new clue. A pair of ladies' shoes,
mud-stained and worn, had been discovered in a ditch on the Hertford
road, four miles from the house where the latest murder had been
committed. This news came by telephone from the Chief of the Hertford
Constabulary, with the further information that the shoes had been
despatched to Scotland Yard by special messenger.

It was half-past seven when the little parcel was deposited on Tarling's
table. He stripped the package of its paper, opened the lid of the
cardboard box, and took out a distorted-looking slipper which had seen
better days.

"A woman's, undoubtedly," he said. "Do you note the crescent-shaped
heel."

"Look!" said Whiteside, pointing to some stains on the whitey-brown inner
sock. "That supports Ling Chu's theory. The feet of the person who wore
these were bleeding."

Tailing examined the slippers and nodded. He turned up the tongue in
search of the maker's name, and the shoe dropped from his hand.

"What's on earth the matter?" asked Whiteside, and picked it up.

He looked and laughed helplessly; for on the inside of the tongue was a
tiny label bearing the name of a London shoemaker, and beneath, written
in ink, "Miss O. Rider."

CHAPTER XXX

WHO KILLED MRS. RIDER?

The matron of the nursing home received Tarling. Odette, she said, had
regained her normal calm, but would require a few days' rest. She
suggested she should be sent to the country.

"I hope you're not going to ask her a lot of questions, Mr. Tarling,"
said the matron, "because she really isn't fit to stand any further
strain."

"There's only one question I'm going to ask," said Tarling grimly.

He found the girl in a prettily-furnished room, and she held out her hand
to him in greeting. He stooped and kissed her, and without further ado
produced the shoe from his pocket.

"Odette dear," he said gently, "is this yours?"

She looked at it and nodded.

"Why yes, where did you find it?"

"Are you sure it is yours?"

"I'm perfectly certain it's mine," she smiled. "It's an old slipper I
used to wear. Why