. But what's
the use? They're all small fry, and we have to keep out a few
lines baited with minnows to catch the Tritons. None of 'em can
do any harm: we watch 'em much too closely for that. Once you've
located your spy, the battle's won. It's when he--or it may be a
she--is running loose, that I get peeved!"

The Chief sprang impatiently to his feet and strode across the
smoking-room, which was all but empty by this time, to get a
match from a table. He resumed his seat with a grunt of
exasperation.

"I can't see light, Okewood!" he sighed, shaking his head.

"But is this all you've got against Nur-el-Din?" asked Desmond.

"No," answered the other slowly, "it isn't. If it were, I need
not have called you in. We would have interned or deported her.
No, we've traced back to her a line leading straight from the
only member of the new organization we have been able to lay by
the heels."

"Then you've made an arrest?"

The Chief nodded.

"A fortnight ago... a respectable, retired English business man,
by name of Basil Bellward... taken with the goods on him, as the
saying is..."

"An Englishman, by Jove!"

"It's hardly correct to call him an Englishman, though he's posed
as an English business man for so long that one is almost
justified in doing so. As a matter of fact, the fellow is a
German named Wolfgang Bruhl and it is my belief that he was
planted in this country at least a dozen years ago solely for the
purpose of furnishing him with good, respectable credentials for
an emergency like this."

"But surely if you found evidence of his connection with this
gang of spies, it should be easy to get a clue to the rest of the
crowd?"

"Not so easy as you think," the Chief replied. "The man who
organized this system of espionage is a master at his craft. He
has been careful to seal both ends of every connection, that is
to say, though we found evidence of Master Bellward-Bruhl being
in possession of highly confidential information relating to the
movements of troops, we discovered nothing to show whence he
received it or how or where he was going to forward it. But we
did find a direct thread leading straight back to Nur-el-Din."

"Really," said Desmond, "that rather complicates things for her,
doesn't it?"

"It was in the shape of a letter of introduction, in French,
without date or address, warmly recommending the dancer to our
friend, Bellward."

"Who is this letter from?"

"It is simply signed 'P