“I’ve thought of that,” said Mr. Garson patiently, “but it’s too real. Whether it was written Sunday or not, it was positively posted Sunday evening and it was positively delivered to Mr. Hemmingway Monday morning. The postmark proves that. Then Mr. Hemmingway opened it, for it is cut open precisely the way he cuts open all his letters, and he dated it with his own dating-stamp, and put it with his lot ‘To be answered.’ Can anything be more convincing of Fiske’s good faith?”
“And yet,” said Bert Bayliss, “it _is_ a faked letter, and George Fiske’s the murderer of Richard Hemmingway!”
“My dear sir, what _do_ you mean?”
“Just what I say. Richard Hemmingway never saw this letter!”
“Can you prove that?”
“I can. Look at the envelope closely with this lens, in a strong light. What do you see between the letters of Mr. Hemmingway’s name?”
“I see”—the Inspector peered closer—“I see faint pencil-marks.”
“Can you make out what they spell?”
“No—yes—‘G-e-o’— _is_ it ‘George Fiske’?”
“It is, though not all the letters are discernible. Fiske wrote this letter on Sunday and mailed it on Sunday, _but_ —he addressed it to himself, _not_ to his employer.”