business?"

"It is the old thing, monsieur. A mystery to be unravelled. Mr. Brenton
here wishes to retain you in his case."

"And what is his case?" was the answer.

Lecocq was evidently pleased to have a bit of real work given him.

[Illustration: The detective.]

Speed briefly recited the facts, Brenton correcting him now and then
on little points where he was wrong. Speed seemed to think these points
immaterial, but Lecocq said that attention to trivialities was the
whole secret of the detective business.

"Ah," said Lecocq, sorrowfully, "there is no real trouble in elucidating
that mystery. I hoped it would be something difficult; but, you see,
with my experience of the old world, and with the privileges one enjoys
in this world, things which might be difficult to one below are very
easy for us. Now, I shall show you how simple it is."

"Good gracious!" cried Speed, "you don't mean to say you are going to
read it right off the reel, like that, when we have been bothering
ourselves with it so long, and without success?"

"At the moment," replied the French detective, "I am not prepared to say
who committed the deed. That is a matter of detail. Now, let us see what
we know, and arrive, from that, at what we do not know. The one fact, of
which we are assured on the statement of two physicians from Cincinnati,