“What astonished me then, and what astonishes me still, as one of the most amazing victories on which I am entitled to pride myself, is that I was able to admit Sauverand and Marie Fauville’s innocence on the spot, as a problem solved once and for all.  It was a first-class performance, I swear, and surpassed the most famous deductions of the most famous investigators both in psychological value and in detective merit.

“After all, taking everything into account, there was not the shadow of a fresh fact to enable me to alter the verdict.  The charges accumulated against the two prisoners were the same, and were so grave that no examining magistrate would have hesitated for a second to commit them for trial, nor any jury to bring them in guilty.  I will not speak of Marie Fauville:  you had only to think of the marks of her teeth to be absolutely certain.  But Gaston Sauverand, the son of Victor Sauverand and consequently the heir of Cosmo Mornington—­Gaston Sauverand, the man with the ebony walking-stick and the murderer of Chief Inspector Ancenis—­was he not just as guilty as Marie Fauville, incriminated with her by the mysterious letters, incriminated by the very revelation of the husband whom they had killed?

“And yet why did that sudden change take place in me?” he asked.  “Why did I go against the evidence?  Why did I credit an incredible fact?  Why did I admit the inadmissible?  Why?  Well, no doubt, because truth has an accent that rings in the ears in a manner all its own.  On the one side, every proof, every fact, every reality, every certainty; on the other, a story, a story told by one of the three criminals, and therefore, presumptively, absurd and untrue from start to finish.  But a story told in a frank voice, a clear, dispassionate, closely woven story, free from complications or improbabilities, a story which supplied no positive solution, but which, by its very honesty, obliged any impartial mind to reconsider the solution arrived at.  I believed the story.”

The explanation which Lupin gave me was not complete.  I asked: 

“And Florence Levasseur?”

“Florence?”

“Yes, you don’t tell me what you thought.  What was your opinion about her?  Everything tended to incriminate her not only in your eyes, because, logically speaking, she had taken part in all the attempts to murder you, but also in the eyes of the police.  They knew that she used to pay Sauverand clandestine visits at his house on the Boulevard Richard-Wallace.  They had found her photograph in Inspector Verot’s memorandum-book, and then—­and then all the rest:  your accusations, your certainties.  Was all that modified by Sauverand’s story?  To your mind, was Florence innocent or guilty?”

He hesitated, seemed on the point of replying directly and frankly to my question, but could not bring himself to do so, and said: 

“I wished to have confidence.  In order to act, I must have full and entire confidence, whatever doubts might still assail me, whatever darkness might still enshroud this or that part of the adventure.  I therefore believed.  And, believing, I acted according to my belief.”