“Here,” be said, “you can hold this as a guarantee that my ticket will be given up.  This lady has been called to the bedside of her mother, who is said to be dangerously ill, and I simply must be allowed to take her to the Royal Devonshire Hotel.”

Luckily, the railwayman had the wit to see. that this earnest-eyed passenger was speaking the truth.

“That’s all right, sir,” he said.  “We have to be very particular about tickets, you know.”

Evelyn Forbes was a few yards in advance, and impatiently awaiting her escort, when a gentleman approached and spoke to her.

“Miss Forbes, I believe,” he said, raising his hat.

“Yes,” she answered breathlessly, because the man’s garb suggested, before he uttered another syllable, that be was a doctor.  He had a curiously foreign aspect, and spoke with a pronounced lisp.

“I am assistant to Dr. Sinnett,” he said, “and he has sent me to take you to the hotel.  This is his car.  Will you come, quick?”

He pointed to a smart limousine drawn up near the exit, and, in his eagerness to be polite, almost pushed the girl toward the open door.  Insensibly, she resisted, and turned to explain matters to Theydon, who had just placated the Cerberus at the gate, and was running alter her.

“Mr. Theydon—­” she began.

“There ith no time to wathe, I athure you,” said Dr. Sinnett’s assistant imperatively.  At that instant Theydon came up.  His temper was ruffled, and he did not scrutinize the doctor’s appearance as closely as might be looked for in one who was actually on his guard against foul play.

“What is it now?” he asked.

“This gentleman has been sent by Dr. Sinnett to take me to the hotel,” said Evelyn.  “Now, Mr. Theydon, perhaps it will be better that you wait for Mr. Handyside and come on at your leisure.”

“I’m a stiff-necked person,” said Theydon, trying to smile unconcernedly.  “I’ve made up my mind to see you safely to your destination, and I refuse to leave you on any account.  I am sure the doctor will let me sit beside the chauffeur.”

Then, for the first time, he glanced at the newcomer, and was almost stupefied to discover that the man, despite his faultless professional attire, was a Chinaman.  Moreover, this Chinaman bore a livid scar down the left side of his face, and his eyes were set horizontally, a sure sign of Manchu descent, because all Southern Chinese have the oblique Mongolian eye.  Though prepared for treachery of some kind, the very simplicity of this scheme almost disconcerted him, and he blurted out the first words that rose to his lips.

“Is your name Wong Li Fu?”

Half unconsciously, a hand dropped to the pocket containing the revolver.  For answer, he was struck a violent blow in the throat and sent sprawling.  The attack was so sudden that he was nearly unprepared for it—­ nearly, not quite, because a flicker of baffled spite in the dark eyes gave him the ghost of a warning.