Helen Cumberly grew slowly quite pallid.

“Good night,” she said; and bowing to the detective and to the surgeon, she prepared to depart.

Mr. Hilton touched Dr. Cumberly’s arm, as he, too, was about to retire.

“May I hope,” he whispered, “that you will return and give me the benefit of your opinion in making out my report?”

Dr. Cumberly glanced at his daughter; and seeing her to be perfectly composed:—­“For the moment, I have formed no opinion, Mr. Hilton,” he said, quietly, “not having had an opportunity to conduct a proper examination.”

Hilton bent and whispered, confidentially, in the other’s ear:—­

“She was drugged!”

The innuendo underlying the words struck Dr. Cumberly forcibly, and he started back with his brows drawn together in a frown.

“Do you mean that she was addicted to the use of drugs?” he asked, sharply; “or that the drugging took place to-night.”

“The drugging did take place to-night!” whispered the other.  “An injection was made in the left shoulder with a hypodermic syringe; the mark is quite fresh.”

Dr. Cumberly glared at his fellow practitioner, angrily.

“Are there no other marks of injection?” he asked.

“On the left forearm, yes.  Obviously self-administered.  Oh, I don’t deny the habit!  But my point is this:  the injection in the shoulder was not self-administered.”

“Come, Helen,” said Cumberly, taking his daughter’s arm; for she had drawn near, during the colloquy—­“you must get to bed.”

His face was very stern when he turned again to Mr. Hilton.

“I shall return in a few minutes,” he said, and escorted his daughter from the room.

VI

AT SCOTLAND YARD

Matters of vital importance to some people whom already we have met, and to others whom thus far we have not met, were transacted in a lofty and rather bleak looking room at Scotland Yard between the hours of nine and ten A. M.; that is, later in the morning of the fateful day whose advent we have heard acclaimed from the Tower of Westminster.

The room, which was lighted by a large French window opening upon a balcony, commanded an excellent view of the Thames Embankment.  The floor was polished to a degree of brightness, almost painful.  The distempered walls, save for a severe and solitary etching of a former Commissioner, were nude in all their unloveliness.  A heavy deal table (upon which rested a blotting-pad, a pewter ink-pot, several newspapers and two pens) together with three deal chairs, built rather as monuments of durability than as examples of art, constituted the only furniture, if we except an electric lamp with a green glass shade, above the table.

This was the room of Detective-Inspector Dunbar; and Detective-Inspector Dunbar, at the hour of our entrance, will be found seated in the chair, placed behind the table, his elbows resting upon the blotting-pad.