us-looking instruments, sat Curlie Carson. To the right of him
was a narrow window. Through that window, a dizzy depth below, lay the
city. Its square, flat roofs formed a mammoth checker-board. Between the
squares criss-crossed the narrow black streets. Like a white chalk-line,
drawn by a careless child, the river wound its crooked way across this
checker-board.

To the left of him was a second narrow window. Through this he caught
the dark gleam of the broad waters of Lake Michigan. Here and there
across the surface twinkled the lamps of a vessel, or flashed the
warning beacon of a lighthouse.

A boy in his late teens was Curlie. Slender, dark, with coal-black eyes,
with curls of the same hue clinging tightly to his well-shaped head, he
had the strong profile and the smooth tapering fingers that might belong
to an artist, a pickpocket or a detective.

An artist Curlie was, an artist in his line--radio. Although still a
boy, he was already an operator of the "commercial, extra first-class"
type. So far as license and title were concerned, he could go no higher.
A pickpocket he was not, but a detective he might be thought to be; a
strange type of detective, however, a detective of the air; the kind
that sits in a small room hundreds of feet in air and listens; listens
to the schemes, the plots, the counterplots of men and to the wild
babble of fools. His task was that of aiding in the capture of knaves
and the silencing of foolish folks who used the newly-discovered
radiophone as their mouthpiece.

"Foolish people," Major Whittaker, Curlie's superior, who had called
him to the service, had said, "do quite as much damage to the radio
service as crooks. Fools and knaves must alike be punished and your task
will be to help catch them."

Wonderful ears had Curlie Carson, perhaps the most wonderful ears in the
world. In catching the fine shadings of diminishing sounds which came to
him through the radio compass, there was not a man who could excel him.

So Curlie sat there surrounded by wire-wrapped frames, coils, keys,
buttons, switches, motors, dry-cells, storage batteries and all the odds
and ends which made up the equipment of the most perfect listening-in
station in the world.

As he sat there with Joe Marion, his pal, by his side, his brow was
wrinkled in thought. He was reviewing the events of the previous night.
At 1:00 a.m., the witching hour when the crooked ones, the mean ones,
come creeping forth like gho