Kennedy took a last look at the den, to make sure that nothing had been disturbed that would arouse suspicion.

“We may as well go,” he remarked.  “To-morrow, I want to be free to make the connection outside with that wire in the shaft.”

Imagine our surprise, the next morning, when a tap at our door revealed Loraine Keith herself.

“Is this Professor Kennedy?” she asked, gazing at us with a half-wild expression which she was making a tremendous effort to control.  “Because if it is, I have something to tell him that may interest Mr. Carton.”

We looked at her curiously.  Without her make-up she was pallid and yellow in spots, her hands trembling, cold, and sweaty, her eyes sunken and glistening, with pupils dilated, her breathing short and hurried, restless, irresolute, and careless of her personal appearance.

“Perhaps you wonder how I heard of you and why I have come to you,” she went on.  “It is because I have a confession to make.  I saw Mr. Haddon just before he was—­kidnapped.”

She seemed to hesitate over the word.

“How did you know I was interested?” asked Kennedy keenly.

“I heard him mention your name with Mr. Carton’s.”

“Then he knew that I was more than a reporter for the Star,” remarked Kennedy.  “Kidnapped, you say?  How?”

She shot a glance half of suspicion, half of frankness, at us.

“That’s what I must confess.  Whoever did it must have used me as a tool.  Mr. Haddon and I used to be good friends—­I would be yet.”

There was evident feeling in her tone which she did not have to assume.  “All I remember yesterday was that, after lunch, I was in the office of the Mayfair when he came in.  On his desk was a package.  I don’t know what has become of it.  But he gave one look at it, seemed to turn pale, then caught sight of me.  ‘Loraine,’ he whispered, ’we used to be good friends.  Forgive me for turning you down.  But you don’t understand.  Get me away from here—­come with me—­call a cab.’

“Well, I got into the cab with him.  We had a chauffeur whom we used to have in the old days.  We drove furiously, avoiding the traffic men.  He told the driver to take us to my apartment—­and—­ and that is the last I remember, except a scuffle in which I was dragged from the cab on one side and he on the other.”

She had opened her handbag and taken from it a little snuff-box, like that which we had seen in the den.

“I—­I can’t go on,” she apologised, “without this stuff.”

“So you are a cocaine fiend, also?” remarked Kennedy.

“Yes, I can’t help it.  There is an indescribable excitement to do something great, to make a mark, that goes with it.  It’s soon gone, but while it lasts I can sing and dance, do anything until every part of my body begins crying for it again.  I was full of the stuff when this happened yesterday; had taken too much, I guess.”