s to secure
your acquittal."

"What is this secret motive that compels Mademoiselle Stangerson to hide
her knowledge from her father?" asked the President.

"That, Monsieur, I do not know," said Rouletabille. "It is no business
of mine."

The President, turning to Monsieur Darzac, endeavoured to induce him to
tell what he knew.

"Do you still refuse, Monsieur, to tell us how you employed your time
during the attempts on the life of Mademoiselle Stangerson?"

"I cannot tell you anything, Monsieur."

The President turned to Rouletabille as if appealing for an explanation.

"We must assume, Monsieur President, that Monsieur Robert Darzac's
absences are closely connected with Mademoiselle Stangerson's secret,
and that Monsieur Darzac feels himself in honour bound to remain silent.
It may be that Larsan, who, since his three attempts, has had everything
in training to cast suspicion on Monsieur Darzac, had fixed on just
those occasions for a meeting with Monsieur Darzac at a spot most
compromising. Larsan is cunning enough to have done that."

The President seemed partly convinced, but still curious, he asked:

"But what is this secret of Mademoiselle Stangerson?"

"That I cannot tell you," said Rouletabille. "I think, however, you
know enough now to acquit Monsieur Robert Darzac! Unless Larsan should
return, and I don't think he will," he added, with a laugh.

"One question more," said the President. "Admitting your explanation, we
know that Larsan wished to turn suspicion on Monsieur Robert Darzac, but
why should he throw suspicion on Daddy Jacques also?"

"There came in the professional detective, Monsieur, who proves himself
an unraveller of mysteries, by annihilating the very proofs he had
accumulated. He's a very cunning man, and a similar trick had often
enabled him to turn suspicion from himself. He proved the innocence of
one before accusing the other. You can easily believe, Monsieur, that so
complicated a scheme as this must have been long and carefully thought
out in advance by Larsan. I can tell you that he had long been
engaged on its elaboration. If you care to learn how he had gathered
information, you will find that he had, on one occasion, disguised
himself as the commissionaire between the 'Laboratory of the Surete' and
Monsieur Stangerson, of whom 'experiments' were demanded. In this way
he had been able before the crime, on two occasions to take stock of the
pavilion. He had 'made up' so th