“What has happened?” asked Blair anxiously.  “I am Mr. Blair.”

The orderly shook his head.  He had delivered his message.  That was all he knew.

“What do you suppose it is?” I asked, as we sped across town in a taxicab.  “Is it the curse that she dreaded?”

Kennedy said nothing and Blair appeared to hear nothing.  His face was drawn in tense lines.

The psychopathic ward is at once one of the most interesting and one of the most depressing departments of a large city hospital, harboring, as it does, all from the more or less harmless insane to violent alcoholics and wrecked drug fiends.

Mrs. Blair, we learned, had been found hatless, without money, dazed, having fallen, after an apparently aimless wandering in the streets.

For the moment she lay exhausted on the white bed of the ward, eyes glazed, pupils contracted, pulse now quick, now almost evanescent, face drawn, breathing difficult, moaning now and then in physical and mental agony.

Until she spoke it was impossible to tell what had happened, but the ambulance surgeon had found a little red mark on her white forearm and had pointed it out, evidently with the idea that she was suffering from a drug.

At the mere sight of the mark, Blair stared as though hypnotized.  Leaning over to Kennedy, so that the others could not hear, he whispered, “It is the mark of the serpent!”

Our arrival had been announced to the hospital physician, who entered and stood for a moment looking at the patient.

“I think it is a drug—­a poison,” he said meditatively.

“You haven’t found out yet what it is, then?” asked Craig.

The physician shook his head doubtfully.  “Whatever it is,” he said slowly, “it is closely allied to the cyanide groups in its rapacious activity.  I haven’t the slightest idea of its true nature, but it seems to have a powerful affinity for important nerve centers of respiration and muscular coordination, as well as for disorganizing the blood.  I should say that it produces death by respiratory paralysis and convulsions.  To my mind it is an exact, though perhaps less active, counterpart of hydrocyanic acid.”

Kennedy had been listening intently at the start, but before the physician had finished he had bent over and made a ligature quickly with his handkerchief.

Then he dispatched a messenger with a note.  Next he cut about the minute wound on her arm until the blood flowed, cupping it to increase the flow.  Now and then he had them administer a little stimulant.

He had worked rapidly, while Blair watched him with a sort of fascination.

“Get Dr. Vaughn,” ordered Craig, as soon as he had a breathing spell after his quick work, adding, “and Professor and Madame Rapport.  Walter, attend to that, will you?  I think you will find an officer outside.  You’ll have to compel them to come, if they won’t come otherwise,” he added, giving the address of the Lodge, as we had found it.