“No, I didn’t.”
“There was no note in that first box giving you the key to the warnings.”
“No...”
“He couldn’t have expected you to catch his meaning from the nature of the individual warnings themselves,” said Ellery with a frown. “To see through a thing like this calls for a certain minimum of education which ― unfortunately, Mr. Priam ― you don’t have. And he knows you don’t have it; he knows you, I think, very well.”
“You mean he sent all these things,” cried Laurel, “not caring whether they were understood or not?”
The question was in Lieutenant Keats’s eyes, too.
“It begins to appear,” said Ellery slowly, “as if he preferred that they weren’t understood. It was terror he was after ― terror for its own sake.” He turned slightly away with a worried look.
“I never did know what they meant,” muttered Roger Priam. “It was not knowing that made me...”
“Then it’s high time you did, Mr. Priam.” Ellery had shrugged his worry off. “The kind of mentality that would concoct such an unusual series of warnings was obviously not an ordinary one. Granted his motive ― which was to inspire terror, to punish, to make his victim die mentally over and over ― he must still have had a mind which was capable of thinking in these specialized terms and taking this specific direction. Why did he choose the stages of evolution as the basis of his warnings? How did his brain come to take that particular path? Our mental processes are directly influenced by our capacities, training, and experience. To have founded his terror campaign on the evolution theory, to have worked it out in such systematic detail, the enemy of Leander Hill and Roger Priam must have been a man of scientific training ― biologist, zoologist, anthropologist... or a naturalist.
“When you think of the stages of evolution,” continued Ellery, “you automatically think of Charles Darwin. Darwin was the father of the evolutionary theory. It was Darwin’s researches over a hundred years ago, his lecture before the Linnaean Society in 1858 on ‘The Theory of Evolution,’ his publication the following year of the amplification of his ‘Theory’ which he called On the Origin of Species, that opened a new continent of scientific knowledge in man’s exploration of his own development.