.', but you shall see it for yourself when
you get the other documents in the case."

"But surely, sir, such a letter might be presented in perfectly
good faith..."

"It might, but not this one. This letter, as an expert has
ascertained beyond all doubt, is written on German manufactured
note-paper of a very superior quality;, the writing is stiff and
angular and not French: and lastly, the French in which it is
phrased, while correct, is unusually pompous and elaborate."

"Then..."

"The letter was, in all probability, written by a German!"

There was a moment's silence. Desmond was thinking despairingly
of the seeming hopelessness of untangling this intricate webwork
of tangled threads.

"And this murder, sir," he began.

The Chief shrugged his shoulders.

"The motive, Okewood, I am searching for the motive. I can see
none except the highly improbable one of Miss Mackwayte being my
confidential secretary. In that case why murder the father, a
harmless old man who didn't even know that his daughter is in my
service, why kill him, I ask you, and spare the girl? On the
other hand, I believe the man Barney's story, and can see that
Marigold does, too. When I first heard the news of the murder
over the telephone this morning, I had a kind of intuition that
we should discover in it a thread leading back to this mesh of
espionage. Is it merely a coincidence that a hair, resembling
Nur-el-Din's, is found adhering to the straps with which Barbara
Mackwayte was bound? I can't think so... and yet..."

"But do you believe then, that Nur-el-Din murdered-old Mackwayte?
My dear Chief, the idea is preposterous..."

The Chief rose from his chair with a sigh.

"Nothing is preposterous in our work, Okewood," he replied. "But
it's 3.25, and my French colleague hates to be kept waiting."

"I thought you were seeing Strangwise, at two?" asked Desmond.

"I put him off until six o'clock," replied the Chief, "he knows
Nur-el-Din, and he may be able to give Marigold some pointers
about this affair. You're off to see Miss Mackwayte now, I
suppose. You know where she's staying? Good. Well, I'll say
good-bye, Okewood. I shan't see you again..."

"You won't see me again? How do you mean, sir?"

"Because you're going back to France!"

"Going back to France? When?"

"By the leave-boat to-night!"

Desmond smiled resignedly.

"My dear Chief," he said, "you must be more explicit. What am I
going back to France for?"

"Why,