“Jump at once,” I commanded.

She obeyed, almost unconscious from fear. She was pretty heavy, and very nearly had me out, too, but I managed to draw back, although the exertion was such that my arms ached for several hours afterwards. I stopped a moment to close the window partly, fearing that if I left it wide open, it might attract the madman’s attention, and that he would be after her before she had time to get to a place of safety.

Turning back into the room, I saw that a bullet had pierced one of the panels of the door around which the fight seemed to be centred. A minute more, and it would give way. I rushed to the other one, and, quickly unlocking it, dashed through the waiting room, and caught the lunatic in the rear. With a bound, I was upon him, my two hands encircling his throat.

“Stand clear of that pistol!” I shouted, as Argot (for it was indeed he) tried to fire over his shoulder. A young man I had not seen before sprang forward, and, seizing his arm, bent it back till it caused a yell of pain and the pistol fell from the madman’s grasp. At this juncture the janitor appeared, and the four of us had little difficulty in overpowering the fellow, although he still fought like a demon. As soon as he was safely bound, I sent my boy to telephone for an ambulance. I now observed, for the first time, that Argot had evidently tried to disguise himself. An enormous pillow, stuffed inside his trousers, and several towels, wound around his shoulders, gave him the appearance of extreme obesity. So, after all, he had been the fat man, and the running footsteps had been his. Well, I was glad that one mystery, at least, was cleared up.

The young stranger, whose opportune appearance had, in all probability, saved my life, still knelt beside the prostrate man, and he and I, together, succeeded in preventing him from breaking his bonds during one of his many paroxysms of frenzy.

“Thank you very much for your timely assistance,” I said; “you are a brave man.”

“Oh, not at all,” he replied; “I am on duty here; I’ve been shadowing this man all the evening.”

We had an awful job getting Argot into the ambulance, and I confess I never felt more relieved in my life than when I saw him safely locked up in a padded cell.

As I was coming away from the hospital, I met Merritt hurrying towards it.