Kennedy bent over and tried to lift her up.  As he did so, the gold bracelet, unclasped, clattered to the floor.

He picked it up and for a moment looked at it.  It was hollow, but in that part of it where it unclasped could be seen a minute hypodermic needle and traces of a liquid.

“A poison bracelet,” he muttered to himself, “one in which enough of a virulent poison could be hidden so that in an emergency death could cheat the law.”

“But this Dr. Hopf,” exclaimed Reginald, who stood behind us looking from the insensible girl to the bracelet and slowly comprehending what it all meant, “she alone knows where and who he is!”

We looked at Kennedy.  What was to be done?  Was the criminal higher up to escape because one of his tools had been cornered and had taken the easiest way to get out?

Kennedy had taken down the receiver of the wall telephone in the room.  A moment later he was calling insistently for his laboratory.  One of the students in another part of the building answered.  Quickly he described the apparatus for vividiffusion and how to handle it without rupturing any of the delicate tubes.

“The large one,” he ordered, “with one hundred and ninety-two tubes.  And hurry.”

Before the student appeared, came an ambulance which some one in the excitement had summoned.  Kennedy quickly commandeered both the young doctor and what surgical material he had with him.

Briefly he explained what he proposed to do and before the student arrived with the apparatus, they had placed the nurse in such a position that they were ready for the operation.

The next room which was unoccupied had been thrown open to us and there I waited with Reginald and Duncan, endeavoring to explain to them the mysteries of the new process of washing the blood.

The minutes lengthened into hours, as the blood of the poisoned girl coursed through its artificial channel, literally being washed of the toxin from the poisoned bracelet.

Would it succeed?  It had saved the life of Buster.  But would it bring back the unfortunate before us, long enough even for her to yield her secret and enable us to catch the real criminal.  What if she died?

As Kennedy worked, the young men with me became more and more fascinated, watching him.  The vividiffusion apparatus was now in full operation.

In the intervals when he left the apparatus in charge of the young ambulance surgeon Kennedy was looking over the room.  In a trunk which was open he found several bundles of papers.  As he ran his eye over them quickly, he selected some and stuffed them into his pocket, then went back to watch the working of the apparatus.

Reginald, who had been growing more and more nervous, at last asked if he might call up Betty to find out how his mother was.

He came back from the telephone, his face wrinkled.

“Poor mother,” he remarked anxiously, “do you think she will pull through, Professor?  Betty says that Dr. Wilson has given her no idea yet about the nature of the trouble.”