and a long finger pointed to the gleaming white square in the road. It
was like an instantaneous photograph--a flash, and the figure had
vanished in the fog.

"This grows interesting," Steel muttered. "Evidently my shadowy friend
has dropped a book of rules in the road for me. The plot thickens."

It was only a plain white card that lay in the road. A few lines were
typed on the back of it. The words might have been curt, but they were to
the point:--

"Go along the sea front and turn into Brunswick Square. Walk along the
right side of the square until you reach No. 219. You will read the
number over the fanlight. Open the door and it will yield to you; there
is no occasion to knock. The first door inside the hall leads to the
dining-room. Walk into there and wait. Drop this card down the gutter
just opposite you."

David read the directions once or twice carefully. He made a mental note
of 219. After that he dropped the card down the drain-trap nearest at
hand. A little way ahead of him he heard the cycle bell trilling as if in
approval of his action. But David had made up his mind to observe every
rule of the game. Besides, he might be rigidly watched.

The spirit of adventure was growing upon Steel now. He was no longer
holding the solid result before his eyes. He was ready to see the thing
through for its own sake. And as he hurried up North Street, along
Western Road, and finally down Preston Street, he could hear the purring
tinkle of the cycle bell before him. But not once did he catch sight of
the shadowy rider.