"It is the envelope of the young lady's letter. Do you know where her aunt, whom she was visiting, lives?"
"At Fontainebleau, I believe."
"Ah; well, this envelope is stamped 'Paris,' Saint-Lazare branch post-office. I know this stamp proves nothing—"
"It is, of course, an indication."
"That is not all; I have read the letter itself—it was here on the table."
M. Plantat frowned involuntarily.
"It was, perhaps, a liberty," resumed M. Lecoq, "but the end justifies the means. Well, you have read this letter; but have you studied it, examined the hand-writing, weighed the words, remarked the context of the sentences?"
"Ah," cried Plantat, "I was not mistaken then—you had the same idea strike you that occurred to me!"
And, in the energy of his excitement he seized the detective's hands and pressed them as if he were an old friend. They were about to resume talking when a step was heard on the staircase; and presently Dr. Gendron appeared.
"Courtois is better," said he, "he is in a doze, and will recover."