We were prisoners!

My mind worked automatically.  At this very moment, perhaps, Baron Kreiger might be negotiating for the electro-magnetic gun.  We had found out where he was, in all probability, but we were powerless to help him.  I thought of Miss Lowe, and picked up the receiver which Kennedy had dropped.

She did not answer.  The wire had been cut.  We were isolated!

Kennedy had jumped to the window.  I followed to restrain him, fearing that he had some mad scheme for climbing out.  Instead, quickly he placed a peculiar arrangement, from the little package he had brought, holding it to his eye as if sighting it, his right hand grasping a handle as one holds a stereoscope.  A moment later, as I examined it more closely, I saw that instead of looking at anything he had before him a small parabolic mirror turned away from him.

His finger pressed alternately on a button on the handle and I could see that there flashed in the little mirror a minute incandescent lamp which seemed to have a special filament arrangement.

The glaring sun was streaming in at the window and I wondered what could possibly be accomplished by the little light in competition with the sun itself.

“Signaling by electric light in the daytime may sound to you ridiculous,” explained Craig, still industriously flashing the light, “but this arrangement with Professor Donath’s signal mirror makes it possible, all right.

“I hadn’t expected this, but I thought I might want to communicate with Burke quickly.  You see, I sight the lamp and then press the button which causes the light in the mirror to flash.  It seems a paradox that a light like this can be seen from a distance of even five miles and yet be invisible to one for whom it was not intended, but it is so.  I use the ordinary Morse code—­two seconds for a dot, six for a dash with a four-second interval.”

“What message did you send?” I asked.

“I told him that Baron Kreiger was at five hundred and one East Fifth, probably; to get the secret service office in New York by wire and have them raid the place, then to come and rescue us.  That was Annenberg.  He must have come up by that trolley we heard passing just before.”

The minutes seemed ages as we waited for Burke to start the machinery of the raid and then come for us.

“No—­you can’t have a cigarette—­and if I had a pair of bracelets with me, I’d search you myself,” we heard a welcome voice growl outside the door a few minutes later.  “Look in that other pocket, Tom.”

The lock grated back and there stood Burke holding in a grip of steel the undersized Annenberg, while the chauffeur who had driven our car swung open the door.

“I’d have been up sooner,” apologized Burke, giving the anarchist an extra twist just to let him know that he was at last in the hands of the law, “only I figured that this fellow couldn’t have got far away in this God-forsaken Ducktown and I might as well pick him up while I had a chance.  That’s a great little instrument of yours, Kennedy.  I got you, fine.”