“Sounds lifelike.” commented Hemingway. “If you ask me, it was his baser self that made him hand you the letter. I wish I could see the envelope, though I don't suppose there was ever a chance that anyone would have been allowed to.”
“The housekeeper saw it,” said the Sergeant. “I remember she told us how she was the one who saw the letter first. On the bedside-table it was. She said it had the one word, Gavin, written on it.”
“It had, had it? Well, it can't be helped: it's a safe bet the housekeeper wouldn't know whether it was Walter's writing, or only a copy of it.”
“What are you getting at?” demanded the Colonel. “Why do you think the envelope may have been significant?”
“Just an idea I've got at the back of my mind, sir,” replied Hemingway, stretching out his hand to pick up the letter. “A little while ago, you were telling me that only three weeks before Walter's death he was saying that he wouldn't have Gavin in the house again, or even see him.”
“But he did have him in the house again. Whatever the quarrel may have been, it was made up.”
“Yes, sir. But it occurs to me that that's exactly what he says in this letter.” Hemingway raised his eyes from the letter, one brow lifting quizzically, but no one spoke. All three men were watching him closely, and in the Colonel's face was an expression of dawning comprehension. “Well,” Hemingway continued, “I've now studied this letter till I'm sick of the sight of it, and, apart from the points I've already mentioned, there's only one thing about it which looks to me a little suspicious. Walter had a sprawling sort of writing, and a trick of joining one word to the next through not bothering to take his pen off the paper. Will you take a look at the date at the top of the page, sir, and tell me what you think?”
He laid the letter down before the Colonel, and, with one accord, Harbottle and Carsethorn moved round the table to obtain a view of it. The Colonel looked closely at it, and then across the desk at Hemingway. “The figure 2 seems rather close to the 5,” he said slowly.
“Look where the light, upward stroke from the Y of May reaches it!” said Hemingway. “It joins the 2 at the bottom of the figure, not, as you'd expect, at the loop at the top. How he made a 2, starting from the bottom of the diagonal line, I can't imagine. But if you carry that faint line from the Y on, in your mind's eye, the way it's going, I think you'll find it would join the 5 exactly where it should, supposing Walter had dated his letter May 5 th, and not May 25 th.”
The Sergeant drew in his breath with a hissing sound; Harbottle cast a glance of grim, vicarious pride at his Chief; the Colonel sat back rather limply in his chair, and said; 'Good God! You think this letter may have been written at the time of the quarrel I told you about— But it's diabolical!”