That, of course, is only an hypothesis." *Although the original English translation often uses the words "murder" and "murderer," the reader may substitute "attack" and "attacker" since no murder is actually committed.
Rouletabille sat down in an armchair, lit his pipe, which he was never without, smoked for a few minutes in silence--no doubt to calm the excitement which, visibly, dominated him--and then replied: "Young man," he said, in a tone the sad irony of which I will not attempt to render, "young man, you are a lawyer and I doubt not your ability to save the guilty from conviction; but if you were a magistrate on the bench, how easy it would be for you to condemn innocent persons!--You are really gifted, young man!" He continued to smoke energetically, and then went on: "No trap will be found, and the mystery of The Yellow Room will become more and more mysterious.

That's why it interests me.

The examining magistrate is right; nothing stranger than this crime has ever been known." "Have you any idea of the way by which the murderer escaped ?" I asked.
"None," replied Rouletabille--"none, for the present.

But I have an idea as to the revolver; the murderer did not use it." "Good Heavens! By whom, then, was it used ?" "Why--by Mademoiselle Stangerson." "I don't understand,--or rather, I have never understood," I said.
Rouletabille shrugged his shoulders.
"Is there nothing in this article in the 'Matin' by which you were particularly struck ?" "Nothing,--I have found the whole of the story it tells equally strange." "Well, but--the locked door--with the key on the inside ?" "That's the only perfectly natural thing in the whole article." "Really!--And the bolt ?" "The bolt ?" "Yes, the bolt--also inside the room--a still further protection against entry?
Mademoiselle Stangerson took quite extraordinary precautions! It is clear to me that she feared someone.

That was why she took such precautions--even Daddy Jacques's revolver--without telling him of it.
No doubt she didn't wish to alarm anybody, and least of all, her father.
What she dreaded took place, and she defended herself.