“I’m afraid you’re missing the most significant thing about the whole message, Della.”
She studied the typewritten copy of the message which Mason pushed across to her. After an interval of silence, she said, “I’m afraid I don’t get it.”
“Look again. It’s relatively simple.”
“You mean that there are no short words in it?”
“That’s one thing,” Mason said. “The shortest word in there has five letters. The longest has six. That’s an interesting peculiarity of the message. Nine words. Three of them have five letters, and the other six have six letters. But there’s something that’s far more significant than that.”
“What?”
“Give up?” he asked banteringly.
She nodded.
“The last fourteen letters of the alphabet aren’t represented there at all,” he said. “The entire message is composed of words made up from the first twelve letters of the alphabet.”
Della Street frowned, stared down at the typewriting, then said thoughtfully, “That’s right. What does it mean?”