, who first discovered the existence of
this interesting doctor, who had already lived in Vauxhall Bridge Road
for eighteen months without arousing suspicion. You have, indeed, a fine
nose for mysteries."

At that moment the telephone, standing upon the big writing-table, rang
loudly, and the man of secrets crossed to it and listened.

"It's Heywood--at Victoria Station. He's asking for you," he exclaimed.

Walter went to the instrument, and through it heard the words: "The boat
train has just gone, sir. Mrs. Caldwell waited for the young lady until
the train went off, but she did not arrive. She seemed annoyed and
disappointed. Dr. Weirmarsh has been on the platform, evidently watching
also."

"Thanks, Heywood," replied Fetherston sharply; "that was all I wanted to
know. Good day."

He replaced the receiver, and, walking back to his friend against the
window, explained: "A simple little inquiry I was making regarding a
departure by the boat train for Paris--that was all."

But he reflected that if Weirmarsh had been watching it must have been to
warn the French police over at Calais of the coming of Enid. No action
was too dastardly for that unscrupulous scoundrel.

Yet, for the present at least, the girl remained safe. The chief peril
was that in which Sir Hugh was placed, now that he had openly defied the
doctor.

On the previous evening he had been in the drawing-room at Hill Street
when Sir Hugh had returned from interviewing the caller. By his
countenance and manner he at once realised that the breach had been
widened.

The one thought by which he was obsessed was how he should save Sir Hugh
from disgrace. His connection with the Criminal Investigation Department
placed at his disposal a marvellous network of sources of information,
amazing as they were unsuspected. He was secretly glad that at last the
old fellow had resolved to face bankruptcy rather than go farther in that
strange career of crime, yet, at the same time, there was serious
danger--for Weirmarsh was a man so unscrupulous and so vindictive that
the penalty of his defiance must assuredly be a severe one.

The very presence of the doctor on the platform of the South Eastern
station at Victoria that morning showed that he did not intend to allow
the grass to grow beneath his feet.

The novelist was still standing near the long window, looking aimlessly
down upon the Embankment, with its hurrying foot-passengers and whirling
taxis.

"Yo