over my head for seven years. That cloud is going to burst very soon,
and it looks as if it were going to do damage."

"I don't understand you, sir," replied the detective, bluntly. "But I
have been put in charge of the most extraordinary case that has ever
come my way and I'll ask you to make yourself as clear as possible."

"I'll do all I can," Nicol Brinn assured him. "But first tell me
something: Why have you come to me for information in respect to Mr.
Paul Harley?"

"I'll answer your question," said Wessex, and the fact did not escape
the keen observing power of Nicol Brinn that the detective's manner had
grown guarded. "He informed Mr. Innes, his secretary, before setting
out, that he was coming here to your chambers."

Nicol Brinn stared blankly at the speaker. "He told him that? When?"

"Yesterday."

"That he was coming here?"

"He did."

Nicol Brinn sat down again upon the settee. "Detective Inspector," said
he, "I give you my word of honour as a gentleman that I last saw Mr.
Paul Harley at ten-fifteen on Wednesday night. Since then, not only have
I not seen him, but I have received no communication from him."

The keen glance of the detective met and challenged the dull glance of
the speaker. "I accept your word, sir," said Wessex, finally, and he
sighed and scratched his chin in the manner of a man hopelessly puzzled.

Silence fell again. The muted sounds of Piccadilly became audible in the
stillness. Cabs and cars rolled by below, their occupants all unaware
of the fact that in that long, museum-like room above their heads lay the
key to a tragedy and the clue to a mystery.

"Look here, sir," said the detective, suddenly, "the result of Mr. Paul
Harley's investigations right up to date has been placed in my hands,
together with all his notes. I wonder if you realize the fact that,
supposing Mr. Harley does not return, I am in repossession of sufficient
evidence to justify me in putting you under arrest?"

"I see your point quite clearly," replied Nicol Brinn. "I have seen my
danger since the evening that Mr. Paul Harley walked into this room: but
I'll confess I did not anticipate this particular development."

"To get right down to business," said Wessex, "if Mr. Paul Harley did
not come here, where, in your idea, did he go?"

Nicol Brinn considered the speaker meditatively. "If I knew that," said
he, "maybe I could help. I told him here in this very room that the pair
of us were walking on