“Far from it. At worst an unhappy victim of his own carelessness in loosing a peril upon his neighborhood. You’re forgetting a connecting link; the secretive red-dot communications from New York City addressed by Moseley to himself on behalf of some customer who ordered simply by a code of ink dots. He was the man I had to find. The giant luna moths helped to do it.”
“I don’t see where they come in at all,” declared Dorr bluntly. “A moth a foot wide couldn’t crawl through a keyhole.”
“No; nor do any damage if it did. The luna is as harmless as it is lovely. In this case the moths weren’t active agents. They were important only as clues—and bait. Their enormous size showed Professor Moseley’s line of work; the selective breeding of certain forms of life to two or three times the normal proportions. Very well; I had to ascertain some creature which, if magnified several times, would be deadly, and which would still be capable of entering a large keyhole. Having determined that—”
“You found what it was?” cried Dorr.
“One moment. Having determined that, I had still to get in touch with Professor Moseley’s mysterious New York correspondent. I figured that he must be interested in Professor Moseley’s particular branch of research or he never could have devised his murderous scheme. So I constructed the luna moth advertisement to draw him, and when I got a reply from Mr. Ross, who is a fellow-tenant of Mr. Dorr’s, the chain was complete. Now, you see where the luna moths were useful. If I had advertised, instead of them, the lathrodectus, he might have suspected and refrained from answering.”
“What’s the lathrodectus?” demanded both the hearers at once.
For answer Average Jones took a letter from his pocket and read:
BUREAU OF ENTOMOLOGY,
U. S. DEPARTMENT OF AGRICULTURE,
WASHINGTON, D. C., April 7
MR. A. V. R. JONES,
Astor Court Temple, New York City.