him, to disappear into the shadow of an adjacent doorway. This
was the house of Reginald Van Der Voor, as Shirley knew. It was
closed because its master, a social acquaintance of the club
man's, was at this time touring the Orient in his steam yacht.
No man should have entered that doorway. So, as the horse
started under the flick of the long whip, Shirley peered
unobserved through the glass window at his side.

A big machine swung up behind the hansom, at some unseen hail,
and the figure came from the doorway, leaping into the car, as it
followed Shirley up the Avenue, a block or so behind.

"It is not always so easy to follow, when the leader knows his
chase," thought Shirley. "I'm glad I'm only a simple club man."

The automobile was unmistakably trailing him, as the hansom
crossed the Plaza, then sped through the Park drive, to the
address he had given his driver.

As Shirley had remembered, this was a large apartment house, in
which one of his bachelor friends lived. He knew the lay of the
building well: next door, with an entrance facing on the side
street was another just like it, and of equal height.

"Wait for me, here," said Shirley. "I'll pay you now, but want
to go to an address down town in five minutes."

He gave the driver a bill, then entered and told the elevator man
to take him to the ninth floor.