“Meaning that he had dipped it in the ink and was just trying it out? Nearer. But take another look, especially at this left-hand end. Don’t you see where the nib has split in the centre to make these two parallel furrows? Well, just observe not only how far apart those furrows are, but also the fact that, though pretty deep, there isn’t a sign of a scratch. Now, then, what does all that tell you? There’s only one sort of pen that could have made those marks, and the answer to that tells you what the marks are.”
Alec pondered dutifully. “A fountain pen! And he was trying to make it write.”
“Wonderful! Alec, I can see you’re going to be a tremendous help in this little game.”
“Well, I don’t see anything to make such a fuss about, even if they were made by a fountain pen. I mean, it doesn’t seem to take us any forrader.”
“Oh, doesn’t it?” Roger had an excellent though somewhat irritating sense of the dramatic. He paused impressively.
“Well?” asked Alec impatiently. “You’ve got something up your sleeve, I know, and you’re aching to get it out. Let’s have it. What do these wonderful marks of yours show you?”
“Simply that the confession is a fake,” retorted Roger happily. “And now let’s go out in the garden.”
He turned on his heel and walked rapidly out on to the sun-drenched lawn. One must admit that Roger had his annoying moments.
The justly exasperated Alec trotted after him. “Talk about Sherlock Holmes!” he growled, as he caught him up. “You’re every bit as maddening yourself. Why can’t you tell me all about it straight out if you really have discovered something, instead of beating about the bush like this?”
“But I have told you, Alexander,” said Roger, with an air of bland innocence. “That confession is a fake.”