e man Boris was coming along the platform
towards him. Tommy allowed him to pass and then took up the chase once
more.

From Waterloo Boris took the tube as far as Piccadilly Circus. Then he
walked up Shaftesbury Avenue, finally turning off into the maze of mean
streets round Soho. Tommy followed him at a judicious distance.

They reached at length a small dilapidated square. The houses there had
a sinister air in the midst of their dirt and decay. Boris looked round,
and Tommy drew back into the shelter of a friendly porch. The place was
almost deserted. It was a cul-de-sac, and consequently no traffic passed
that way. The stealthy way the other had looked round stimulated Tommy's
imagination. From the shelter of the doorway he watched him go up the
steps of a particularly evil-looking house and rap sharply, with a
peculiar rhythm, on the door. It was opened promptly, he said a word or
two to the doorkeeper, then passed inside. The door was shut to again.

It was at this juncture that Tommy lost his head. What he ought to have
done, what any sane man would have done, was to remain patiently where
he was and wait for his man to come out again. What he did do was
entirely foreign to the sober common sense which was, as a rule, his
leading characteristic. Something, as he expressed it, seemed to snap in
his brain. Without a moment's pause for reflection he, too, went up the
steps, and reproduced as far as he was able the peculiar knock.

The door swung open with the same promptness as before. A
villainous-faced man with close-cropped hair stood in the doorway.

"Well?" he grunted.

It was at that moment that the full realization of his folly began to
come home to Tommy. But he dared not hesitate. He seized at the first
words that came into his mind.

"Mr. Brown?" he said.

To his surprise the man stood aside.

"Upstairs," he said, jerking his thumb over his shoulder, "second door
on your left."

CHAPTER VIII. THE ADVENTURES OF TOMMY

TAKEN aback though he was by the man's words, Tommy did not hesitate.
If audacity had successfully carried him so far, it was to be hoped
it would carry him yet farther. He quietly passed into the house and
mounted the ramshackle staircase. Everything in the house was filthy
beyond words. The grimy paper, of a pattern now indistinguishable,
hung in loose festoons from the wall. In every angle was a grey mass of
cobweb.

Tommy proceeded leisurely. By the time he reached th