"Six hundred!" exclaimed Curlie in a tense whisper. "Why, that's what they use for S.O.S. at sea! It's criminal. Endangers every ship in distress. Five years in prison for it. Get him, can't you?"
"Can't. That's the trouble. Every time I think I've got him spotted he seems to move."
"To move!"
"Yes, sir."
"That's queer! I'll be up right away."
"Come on," exclaimed Curlie, grabbing his hat and dragging Joe to his feet. "It's a big one. Moves, he says. Sends 600; big power. Bet it's that same hotel fellow. Gee whiz! Supposing it turned out to be that sixteenth story girl and she caught me spying on her. I tell you it's something big!"
Impatient at the slowness of the up-shooting elevator, Curlie at last leaped out before the iron door at the top was half open, then two steps at a time sprang up a flight of stairs. Out of breath, he arrived at the final landing, sprang through the door to the secret tower room, then seizing his headpiece, sank into a chair.
By a single move of the hand, Coles Masters indicated the radio-compass he had been listening in on.
"That's where he was, last time he spoke," he grumbled, "but no telling where he'll be next. He's been dodging all over that stretch of country."
Curlie's fingers moved rapidly. He adjusted the coil of a radio-compass here, another there and still another here. He twisted the knob of each to the 600 mark, then, twisting the tuning knobs, lined them all up to receive on the same wave length. The winding of each was set at a slightly different angle from any other.