look here," exclaimed M. Filleul, "you're trying to take me in!
This won't do, you know; a joke can go too far!"

"I must say, Monsieur le Juge d'Instruction, that your astonishment
surprises me. What is there to prevent my being a sixth-form pupil at
the Lycee Janson? My beard, perhaps? Set your mind at ease: my beard is
false!"

Isidore Beautrelet pulled off the few curls that adorned his chin, and
his beardless face appeared still younger and pinker, a genuine
schoolboy's face. And, with a laugh like a child's, revealing his white
teeth:

"Are you convinced now?" he asked. "Do you want more proofs? Here, you
can read the address on these letters from my father: 'To Monsieur
Isidore Beautrelet, Indoor Pupil, Lycee Janson-de-Sailly.'"

Convinced or not, M. Filleul did not look as if he liked the story. He
asked, gruffly:

"What are you doing here?"

"Why--I'm--I'm improving my mind."

"There are schools for that: yours, for instance."

"You forget, Monsieur le Juge d'Instruction, that this is the
twenty-third of April and that we are in the middle of the Easter
holidays."

"Well?"

"Well, I have every right to spend my holidays as I please."

"Your father--"

"My father lives at the other end of the country, in Savoy, and he
himself advised me to take a little trip on the North Coast."

"With a false beard?"

"Oh, no! That's my own idea. At school, we talk a great deal about
mysterious adventures; we read detective stories, in which people
disguise themselves; we imagine any amount of terrible and intricate
cases. So I thought I would amuse myself; and I put on this false
beard. Besides, I enjoyed the advantage of being taken seriously and I
pretended to be a Paris reporter. That is how, last night, after an
uneventful period of more than a week, I had the pleasure of making the
acquaintance of my Rouen colleague; and, this morning, when he heard of
the Ambrumesy murder, he very kindly suggested that I should come with
him and that we should share the cost of a fly."

Isidore Beautrelet said all this with a frank and artless simplicity of
which it was impossible not to feel the charm. M. Filleul himself,
though maintaining a distrustful reserve, took a certain pleasure in
listening to him. He asked him, in a less peevish tone:

"And are you satisfied with your expedition?"

"Delighted! All the more as I had never been present at a case of the
sort and I find that this one is not lacking in inter