sage was sent. Tough luck!" he muttered. "Can't
tell a thing here."

Glancing to his right, he sat up with a start. He had suddenly become
aware of the fact that he was just before the gate of the estate of J.
Anson Ardmore, reputed to be the richest man of the city.

"Huh!" Curlie grunted. "Car must have stood about here when that last
message was sent. Maybe it went up that lane. Maybe it didn't, too. J.
Anson's got a son, about my age I guess. Vincent they call him. He might
be up to something. There's a girl, too, sixteen or so. Can't tell what
these rich folks will do."

He stepped down the rich man's private drive, but here the surface of
crushed stone was so perfectly kept that no telltale mark was to be
seen.

He did not venture far, as he had no relish for being caught trespassing
on such an estate without some good explanation for his conduct. Just at
that moment he had no desire to explain.

As he turned to go back, he caught the thud-thud of hoof beats along the
private drive.

Fortunately the abundant shrubbery hid him from view. Hardly had he
reached the machine and assumed the attitude of one hunting trouble in
his engine when a girl rounded a corner at full gallop.

Dressed in full riding costume and mounted on a blooded horse, she swung
along as graceful as a lark. As she came into the public highway she
flashed Curlie a look and a smile. Then she was gone.

Curlie liked the smile even if it did come from one of the "four
hundred."

"Gee! Old Humming Bird," he exclaimed as he patted his car, "did she
mean that smile for you or for me? So there might be a girl in the case,
same as there seems to be in that one over at the hotel? Girl in most
every case. What if she sent those messages and I found her out? That
would sure be tough.

"But business is business!" He set his mouth grimly. "You can't fool
with old Uncle Sam, not when you're endangering the lives of some of
his bravest sons at sea."

He threw in the clutch and drove slowly along the road. Twice he paused
to examine the tracks made the night before. Each time he discovered
marks of the diamond tread.

"That radiophone was mounted on a car," he decided; "I'll stake my life
on that. Now if he keeps it up, how am I to catch him?"

CHAPTER III

A WHISPER IN THE NIGHT

The next night found Curlie in the secret tower room alone. Joe Marion
was away helping to run down a case of "malicious interference."

It was curious bu