e?"

"I shall do nothing of the sort," was The Sparrow's reply. "The lad is
in serious peril. I happen to know that."

"Then why don't you warn him at once?"

"That's my affair!" snapped the gentleman known in Mayfair as Mr.
Peters.

"IF Henfrey is here, then I'd like to meet him," Howell said.

It seemed as though the pair were in a room on the opposite side of the
passage, and yet, though Hugh stood at some distance away, he could hear
the words quite distinctly. At this he was much surprised. He did not,
however, know that in that house in Ellerston Street there had been
constructed a curious system of ventilation of the rooms by which a
conversation taking place in a distant apartment could be heard in
certain other rooms.

The fact was that The Sparrow received a good many queer visitors, and
some of their whispered conversations while they awaited him were often
full of interest.

The house was, in more than one way, a curiosity. It had a secret exit
through a mews at the rear--now converted into a garage--and several
other mysterious contrivances which were unsuspected by visitors.

"It would hardly do for him to know what we know, Mr. Peters--eh?"
Hugh heard Howell say a moment later. It was the habit of The Sparrow's
accomplices to address their great director--the brain of criminal
Europe--by the name under which they inquired for him. The Sparrow had
twenty names--one for every city in which he had a cosy _pied-a-terre_.
In Paris, Lisbon, Madrid, Marseilles, Vienna, Hamburg, Budapest,
Stockholm and on the Riviera, he was, in all the cities, known by a
different name. Yet each was so distinct, and each individuality so well
kept up, that he snapped his fingers at the police and pitied them their
red tape, ignorance, and lack of initiative.

Truly, Il Passero, the cosmopolitan of many names and half a dozen
nationalities, had brought criminality to a fine art.

Hugh, standing there breathless, listened to every word. Who was this
man Howell?

"Hush!" cried The Sparrow suddenly. "What a fool I am! I quite forgot
to close the ventilator in the room to which the young fellow has been
shown! I hope he hasn't overheard! I had Evans and Janson in there an
hour ago, and they were discussing me, as I expected they would! It was
a good job that I took the precaution of opening the ventilator, because
I learned a good deal that I had never suspected. It has placed me on
my guard. I'll go and get young Henfr