er
who, doubtless, regarded the whole affair as a joke. It was _not_ a joke!

So, as part of his day's work, M. Paul had taken steps for the finding of
this smallish object dropped into the Seine by Pussy Wilmott, and, betimes
on the morning after that lady's examination, a diver began work along the
Concorde bridge under the guidance of a young detective named Bobet,
selected for this duty by M. Paul himself. This was _one_ thread to be
followed, a thread that might lead poor Bobet through weary days and nights
until, among all the hardware shops in Paris, he had found the particular
one where that particular auger had been sold!

Another thread, meanwhile, was leading another trustworthy man in and out
among friends of Martinez, whom he must study one by one until the false
friend had been discovered. And another thread was hurrying still another
man along the trail of the fascinating Anita, for Coquenil wanted to find
out _why_ she had changed her mind that night, and what she knew about the
key to the alleyway door. Somebody gave that key to the assassin!

Besides all this, and more important, M. Paul had planned a piece of work
for Papa Tignol when the old man reported for instructions this same
Wednesday morning just as the detective was finishing his chocolate and
toast under the trees in the garden.

"Ah, Tignol!" he exclaimed with a buoyant smile. "It's a fine day, all the
birds are singing and--we're going to do great things." He rubbed his hands
exultantly, "I want you to do a little job at the Hotel des Etrangers,
where Kittredge lived. You are to take a room on the sixth floor, if
possible, and spend your time playing the flute."

"Playing the flute?" gasped Tignol. "I don't know how to play the flute."

"All the better! Spend your time learning! There is no one who gets so
quickly in touch with his neighbors as a man learning to play the flute."

"Ah!" grinned the other shrewdly. "You're after information from the sixth
floor?"

M. Paul nodded and told his assistant exactly what he wanted.

"Eh, eh!" chuckled the old man. "A droll idea! I'll learn to play the
flute!"

"Meet me at nine to-night at the Three Wise Men and--good luck. I'm off to
the Sante."

As he drove to the prison Coquenil thought with absorbed interest of the
test he was planning to settle this question of the footprints. He was
satisfied, from a study of the plaster casts, that the assassin had limped
slightly on his left foot