papers. They must be very valuable to have been put away in a safe,
and the key to which to be of so much importance. Perhaps a thought of
blackmail occurred to him as a useful possibility in helping him in
his designs on Mademoiselle Stangerson. He quickly made a parcel of the
papers and took it to the lavatory in the vestibule. Between the time of
his first examination of the pavilion and the night of the murder of the
keeper, Larsan had had time to find out what those papers contained.
He could do nothing with them, and they were rather compromising.
That night he took them back to the chateau. Perhaps he hoped that, by
returning the papers he might obtain some gratitude from Mademoiselle
Stangerson. But whatever may have been his reasons, he took the papers
back and so rid himself of an encumbrance."

Rouletabille coughed. It was evident to me that he was embarrassed.
He had arrived at a point where he had to keep back his knowledge of
Larsan's true motive. The explanation he had given had evidently been
unsatisfactory. Rouletabille was quick enough to note the bad impression
he had made, for, turning to the President, he said: "And now we come to
the explanation of the Mystery of The Yellow Room!"

A movement of chairs in the court with a rustling of dresses and an
energetic whispering of "Hush!" showed the curiosity that had been
aroused.

"It seems to me," said the President, "that the Mystery of The Yellow
Room, Monsieur Rouletabille, is wholly explained by your hypothesis.
Frederic Larsan is the explanation. We have merely to substitute him for
Monsieur Robert Darzac. Evidently the door of The Yellow Room was open
at the time Monsieur Stangerson was alone, and that he allowed the man
who was coming out of his daughter's chamber to pass without arresting
him--perhaps at her entreaty to avoid all scandal."

"No, Monsieur President," protested the young man. "You forget that,
stunned by the attack made on her, Mademoiselle Stangerson was not in
a condition to have made such an appeal. Nor could she have locked
and bolted herself in her room. You must also remember that Monsieur
Stangerson has sworn that the door was not open."

"That, however, is the only way in which it can be explained. The Yellow
Room was as closely shut as an iron safe. To use your own expression, it
was impossible for the murderer to make his escape either naturally or
supernaturally. When the room was broken into he was not there! He mus