I was telephoning excitedly Garrick’s instructions and as he waited for me to finish he was taking a last turn at the optophone before we made our dash on Warrington’s.

A suppressed exclamation escaped him.  I turned toward him quickly from the telephone and hung up the receiver.

“What’s the matter?” I asked anxiously.

For a moment he did not reply, but seemed to be listening with an intensity that I knew betokened something unexpected.

“Tom,” he cried abruptly, stripping the receiver from his head with a jerk and clapping it over my own ears, “quick!—­tell me what you hear.  What does it sound like to you?  What is it?  I can’t be mistaken.”

I listened feverishly.  Not having had a former acquaintance with the machine, I did not know just what to make of it.  But from the receiver of the little optophone there seemed to issue the most peculiar noise I had ever heard a mechanical instrument make.

It was like a hoarse rumbling cry, now soft and almost plaintive, again louder and like a shriek of a damned soul in the fires of the nether world.  Then it died down, only to spring up again, worse than before.

If I had been listening to real sounds instead of to light I should have been convinced that the thing was recording a murder.

I described it as best I could.  The fact was that the thing almost frightened me by its weird novelty.

“Yes—­yes,” agreed Garrick, as the sensations I experienced seemed to coincide with his own.  “Exactly what I heard myself.  I felt sure that I could not be mistaken.  Quick, Tom,—­get central on that wire!”

A moment later he seized the telephone from me.  I had expected him to summon the police to assist us in capturing two crooks who had, perhaps, devised some odd and scientific method of blowing up a safe.

“Hello, hello!” he shouted frantically over the wire.  “The fire department!  This is eight hundred Seventy-second—­on the corner; yes, yes—­northeast.  I want to turn in an alarm.  Yes—­quick!  There is a fire—­a bad one—­incendiary—­top floor.  No, no—­I’m not there.  I can see it.  Hurry!”

CHAPTER XIV

THE ESCAPE

He had dropped the telephone receiver without waiting to replace it on the hook and was now dashing madly out of the empty apartment and down the street.

The hall-boy at Warrington’s had done exactly as I had ordered him.  There was the elevator waiting as Garrick gave the five short rings at the nightbell and the outside door was unlocked.  No one had yet discovered the fire which we knew was now raging on the top floor of the apartment.

We were whirled up there swiftly, just as we heard echoing through the hall and the elevator shaft from someone who had an apartment on the same floor the shrill cry of, “Fire, fire!”

Tenants all the way up were now beginning to throw open their doors and run breathlessly about in various states of undress.  The elevator bell was jangling insistently.