Poirot laughed heartily.
“_Une blague!_ For the benefit of the valet. The card was one with
a specially prepared surface—for finger-prints. I went straight
to Scotland Yard, asked for our old friend Inspector Japp, and laid
the facts before him. As I had suspected, the finger-prints proved
to be those of two well-known jewel thieves who have been ‘wanted’
for some time. Japp came down with me, the thieves were arrested,
and the necklace was discovered in the valet’s possession. A clever
pair, but they failed in _method_. Have I not told you, Hastings,
at least thirty-six times, that without method——”
“At least thirty-six thousand times!” I interrupted. “But where
did their ‘method’ break down?”
“_Mon ami_, it is a good plan to take a place as chambermaid or
valet—but you must not shirk your work. They left an empty room
undusted; and therefore, when the man put down the jewel-case on
the little table near the communicating door, it left a square
mark——”
“I remember,” I cried.
“Before, I was undecided. Then—I _knew_!” There was a moment’s
silence.
“And I’ve got my pearls,” said Mrs. Opalsen as a sort of Greek
chorus.
“Well,” I said, “I’d better have some dinner.” Poirot accompanied
me.
“This ought to mean kudos for you,” I observed.
“_Pas du tout_,” replied Poirot tranquilly. “Japp and the local
inspector will divide the credit between them. But”—he tapped his
pocket—“I have a cheque here, from Mr. Opalsen, and, how say you,
my friend? This week-end has not gone according to plan. Shall we
return here next week-end—at my expense this time?”