Della Street was sitting at her desk frantically scribbling with a pencil when Mason returned, an oblong package under his arm.
“Get it?” he asked.
“Uh huh. That ten plus two crack did it.”
“Got it deciphered?”
She said, “I’ve got it figured both ways. Either the figures start with a and end with j, or they start with c and end with l. ”
“They start with c and end with l, ” Mason said. “The a and b are true letters.”
“How do you know?”
“Because the a and b are always either the second or third letter from the end of the word.”
“Well, I’ve got it worked out that way,” she said.
“How does it check out?”
She said, “Well, if c represents one; d represents two; e, three; f, four; g, five; h, six; i, seven; j, eight; k, nine; and l a cipher, the message breaks down into 192A19 187A8 20A11 632B13 137A22 579A21 1025B2 94B16 1055B8.”
“I think we can safely rely on that,” Mason said.
“But that’s a code within a code,” she said. “It still doesn’t give us the message.”
“No,” Mason said, untying the string around the oblong package, “but I think this will.”
“What is it?”
“There are two books that might have been used as keys, two books that would naturally have large vocabularies, and in which the pages would be divided into an A column and a B column. They’re the Bible and the dictionary.”
“And because Junior mentioned his dictionary, you think...”
“There’s been a lot of talk about a dictionary,” Mason agreed, taking the wrappings off the package. “No one’s said very much about a Bible. Junior has his dictionary, and he isn’t able to keep his hands on it because his Aunt Rebecca is constantly borrowing it. She says that her interest in it is due to crossword puzzles, but that might not be true. In any event, the dictionary looks like a good lead.”
“How do you know which dictionary?”
“I happened to notice the dictionary on the table when I was out at Gentries’. It’s a Webster’s Collegiate Dictionary, Fifth Edition.”
“Then the numbers refer to pages?”
“That’s right. For instance, the first word in the code message would be the nineteenth word from the top in the A column on page 192.”
“And the A column would be the first one?”
“That’s right. The one on the left.”
Della Street said, “Gosh, Chief, I’m so excited. I’m trembling. Let’s see what it is.”
Mason turned the pages in the dictionary, then counted down the column.
“What is it?” she asked.
“Coast,” Mason said.
“Coast.” She frowned. “That doesn’t sound right.”
“Well, let’s try the next one. What is it?”
“The eighth word in the left-hand column on page 187.”
Mason turned back a few pages in the dictionary, then announced, “That word’s ‘clear.’ What’s the next one?”
Della Street’s voice showed her excitement. “Gosh, Chief, that makes it ‘Coast clear.’ Let’s see. The next one’s the eleventh word in the A column on page 20.”
Mason made a brief search, then announced, “That’s ‘after.’ What comes next?”
“The thirteenth word in the B column on page 632.”
When Mason found that word, he whistled.
“What is it?” she demanded impatiently.
“Midnight,” Mason said. “Get it? ‘Coast clear after midnight.’ ”
“We’ve got it. We’ve got it,” she said. “And the crime was committed after midnight. It ties up. This is the solution of the whole business.”
“Don’t be too certain,” Mason warned. “What’s our next word?”
“The twenty-second word in the A column on page 137.”
“But,” Mason announced after a moment. “What’s next?”
“The twenty-first word in the A column on page 579.”
Mason turned pages. “Lift,” he said. “What’s next?”
“The second word in the B column on page 1025. Gosh, Chief, hurry.”
Mason turned the pages. Once more he gave a low whistle.
“What is it?”
“Telephone receiver,” Mason said.
Della Street regarded him with startled eyes. “ ‘Coast clear after midnight but lift telephone receiver.’ And the police found fingerprints on the telephone receiver!”
“That’s right. What’s next?”
“The sixteenth word in the B column on page 94.”
“Before,” Mason announced. “What’s the last word?”
“The eighth word in the B column on page 1055.”
Mason turned the pages and said, “That’s ‘touching.’ That gives us the message, Della. ‘Coast clear after midnight, but lift telephone receiver before touching.’ ”
“Before touching what?” she asked.
He shrugged his shoulders. “Obviously not the telephone receiver. You can’t lift a telephone receiver without touching it.”
“What are you going to do about this, Chief?”
“Darned if I know.”
“Going to tell Tragg?”
“I think not — not yet.”
“And you think this implicates Rebecca?”
He said, “I don’t know. After all, Arthur Gentrie was the one who got the message, and apparently the only one. That tin was left there for a purpose. It contained a message. The person who left it knew it contained a message, and the person who was to have received the message knew that it contained a message. Apparently, the only one who made any attempt to open the can was Arthur Gentrie.”
“But he was in bed at the time the shot was fired.”
“Exactly.”
The telephone, which was connected with Mason’s private unlisted line — a number which less than half a dozen people had — buzzed into activity. Mason picked up the receiver, said, “Let’s have it.”
Paul Drake’s voice said. “Giving you a hot tip right off the bat, Perry.”
“What is it?”
“Remember I told you there were fingerprints on the telephone receiver?”
“Yes.”
“Tragg isn’t saying anything just yet, but he’s found out whose prints they are.”
“Whose?”
“Arthur Gentrie’s.”
“The old man,” Mason said triumphantly. “I was just telling Della that...”
“No,” Drake interrupted. “The young chap — the one they call Junior.”
Mason frowned. “Darn it, Paul. You kick the props out from under me just when I’m showing off to my secretary. Why the hell couldn’t you have waited a half hour with that information?”
“Well,” Drake said cheerfully, “that’s the way with theories. You form them, and they get upset.”
“But everything in this pointed absolutely to one logical conclusion,” Mason said. “It just doesn’t fit in to have those fingerprints belong to young Gentrie.”
“Well, they’re his prints all right. Keep it under your hat. I got a straight tip from one of the newspaper boys. Tragg isn’t saying anything. The newspaper guys got it straight from the fingerprint man in the D.A.’s office, but had to promise not to use it until he got a release. Apparently, Tragg’s going to give the boy a little rope and see if he’ll get himself tangled up.”
“Okay,” Mason said, “keep me posted, Paul.” He dropped the receiver into place, looked at Della Street, and shook his head. “The darn thing just doesn’t fit.”
“They’re Junior’s fingerprints?” she asked.
He nodded.
“Then the message must have been for him.”
Mason pushed his hands down deep in his pockets. “That is what comes of sticking my neck out,” he announced.