“Not an alibi, nothing?” murmured the old fellow.  “No explanations?  The idea!  It is inconceivable!  Not an alibi?  We must then be mistaken:  he cannot be the criminal.  That is certain!”

The investigating magistrate felt that the old amateur must have been waiting the result of the examination at the wine shop round the corner, or else that he had gone mad.

“Unfortunately,” said he, “we are not mistaken.  It is but too clearly shown that M. de Commarin is the murderer.  However, if you like, you can ask Constant for his report of the examination, and read it over while I put these papers in order.”

“Very well,” said the old fellow with feverish anxiety.

He sat down in Constant’s chair, and, leaning his elbows on the table, thrusting his hands in his hair, he in less than no time read the report through.  When he had finished, he arose with pale and distorted features.

“Sir,” said he to the magistrate in a strange voice, “I have been the involuntary cause of a terrible mistake.  This man is innocent.”

“Come, come,” said M. Daburon, without stopping his preparations for departure, “you are going out of your mind, my dear M. Tabaret.  How, after all that you have read there, can—­”

“Yes, sir, yes:  it is because I have read this that I entreat you to pause, or we shall add one more mistake to the sad list of judicial errors.  Read this examination over carefully; there is not a reply but which declares this unfortunate man innocent, not a word but which throws out a ray of light.  And he is still in prison, still in solitary confinement?”

“He is; and there he will remain, if you please,” interrupted the magistrate.  “It becomes you well to talk in this manner, after the way you spoke last night, when I hesitated so much.”

“But, sir,” cried the old detective, “I still say precisely the same.  Ah, wretched Tabaret! all is lost; no one understands you.  Pardon me, sir, if I lack the respect due to you; but you have not grasped my method.  It is, however, very simple.  Given a crime, with all the circumstances and details, I construct, bit by bit, a plan of accusation, which I do not guarantee until it is entire and perfect.  If a man is found to whom this plan applies exactly in every particular the author of the crime is found:  otherwise, one has laid hands upon an innocent person.  It is not sufficient that such and such particulars seem to point to him; it must be all or nothing.  This is infallible.  Now, in this case, how have I reached the culprit?  Through proceeding by inference from the known to the unknown.  I have examined his work; and I have formed an idea of the worker.  Reason and logic lead us to what?  To a villain, determined, audacious, and prudent, versed in the business.  And do you think that such a man would neglect a precaution that would not be omitted by the stupidest tyro?  It is inconceivable.  What! this man is so skillful as to leave such feeble traces that they escape Gevrol’s practised eye, and you think he would risk his safety by leaving an entire night unaccounted for?  It’s impossible!  I am as sure of my system as of a sum that has been proved.  The assassin has an alibi.  Albert has pleaded none; then he is innocent.”