driver and as the car turned up Fifth Avenue, he studied this missive
with knit brows.

"A new worry?" asked Helene. "May I help you?"

He handed her the letter, and she noticed the nervous handwriting. It
was short.

"Dear Mr. Shirley: Just received a threatening note demanding money. Can
you come up at once? Howard V. C."

Shirley answered the question in the blue eyes, as she finished.

"As I thought it would turn out. Baffled in their game of robbing old
men who have all left the city, they have begun to work the chance for
blackmail. I will advise Van Cleft to pay them, and then we will follow
the money. Here is the mansion and I will be out in five minutes."

He soon disappeared behind the bronze door. True to his promise, in five
minutes he had returned. He looked up and down the Avenue amazed. Not a
trace of the taxicab, nor of Helene Marigold could be seen!

Shirley's impulse was to pinch himself to awaken from the chimera. He
knew she was armed, and would use the weapon if only to call for help.
For the first time in his career the chill of terror crept into his
heart--not for himself, but an irresistible dread of some impending
danger for this unfathomable woman who had shared his dangers so
uncomplainingly during this last wonderful day. He racked his mind
vainly for some plausible reason. "She knows I need her. Yet at the
supreme moment of the game she disappears. Can she be like other women,
when she is most necessary?"

And he walked slowly down the Avenue, disconcerted, endeavoring to solve
this sudden abortion of his best laid plans.

CHAPTER XV. CONCERNING HELENE'S FINESSE

Shirley endured a miserable three hours, in his attempts to locate the
girl. She had not returned to the Hotel California, and he returned to
the club in moody reflection. It was beginning to snow, and the ground
was soon covered with a thin coat of white, through which he noticed his
footprints stenciled against the black of the wet pavement. He wasted a
dozen matches in the freshening wind, as he tried to light a cigarette.
He stepped into a doorway on the Avenue to avail himself of its shelter.
As he turned out to the street again, he almost bumped into two men,
wearing black caps! One of them grunted a curt apology, as he stepped
on.

"They are after me as usual," he thought. "Why not reverse operations
and find out where they belong?"

It seemed hopeless: as in a checker game they had him at disadvantage