Scotty's forehead furrowed. "Which one did he memorize? It was an old one, but I can't remember the date."

"Got it," Rick said. "Remember the letter L? The twelfth letter of the alphabet. It must be the 1912 edition."

Scotty surveyed the shelf. "Which we don't have," he said.

Rick groaned. "No!"

Hartson Brant called from the dining room. "Haven't you solved that cipher yet?"

The boys walked dejectedly back to join the others. Rick explained that the right volume was missing. The Spindrift files just didn't go back that far.

"Sit down and eat your dinner," Hartson Brant said. He sliced roast for them, his eyes thoughtful. "Something's wrong with your reasoning," he said, as he filled Rick's plate. "Would Chahda have a 1912 edition with him in Singapore? I doubt it. More likely he'd have a more recent one."

"But the letter L has to mean something," Barby protested.

"What could it mean but twelve?" Rick asked, and the answer struck him before the words were out. He shouted, "I know! It could mean fifty! L is the Roman numeral fifty."

Barby clapped her hands. Scotty reached over and pounded Rick on the back.

"That's it," Hartson Brant said approvingly. "I'll make a wager on it.

Chahda used the 1950 edition."

Rick pushed back his chair, but the scientist's voice stopped him.

"Let's rest on our laurels, Rick. Finish dinner first, then we'll all retire to the library and work it out."

Because they were burning with impatience, the three younger members of the Spindrift family did not enjoy the meal, but they made a pretense of eating. Then, an eternity later, Hartson Brant took the last sip of his coffee and grinned at Rick. "Shall we get to it?"

"Shall we!" Barby led the way, holding the cable high.

The first part was easy. Since most pages in the _Almanac_ had three numbers, they a.s.sumed that the first three numbers in each code group referred to the page. Similarly, they a.s.sumed that the second two numbers referred to the line. That left two numbers for the position of the word on the line.

With nervous fingers Rick turned to Page 521 of the 1950 edition and counted down 30 lines. He hesitated over the subt.i.tles, then decided to count them too. At the proper line, he looked up at Scotty and Barby who were watching over his shoulder.

"But there are two columns."

"Don't worry about the columns," Scotty advised. "I don't think Chahda would pay any attention to the columns, because it would mean extra numbers in each group. Count right across and don't pay any attention to the dividing line."

Rick did so. "It doesn't come out right," he complained. "The number is 39, but there are only 17 words on the whole line."

Barby sighed. "Maybe we're wrong all the way around."

"I don't think so," Hartson Brant said. He was sitting in a comfortable chair, smoking an after-dinner pipe. "The logic of the thing appeals to me. Do you suppose Chahda would know about nulls?"

"What's a null?" Scotty asked.

"In cryptography it's a number, or letter, thrown in for the sake of appearance, or to confuse."

"Chahda might know," Rick said. "That brown head of his is crammed full of more odd chunks of information than you could imagine. But if there's a null in this, which figure is it?"

"Try it both ways," Barby urged. "Here, I'll do it." She counted across the line. "The third word is 'seventeen.'" She wrote it down. "The ninth word is 'come.'"

"Could be either," Scotty mused. "But 'come' sounds more likely. Let's try the next group."

That was 6231581. Rick turned to Page 623 and counted down 15 lines, including the t.i.tle. However, he didn't count the page heading. The heading was on the same line as the page number. Both were above a line drawn across the top of the page, and it seemed sensible to start below the line.

"There aren't 81 words on the lines," he said. "So that means another null, maybe. The first word is 'both' and the eighth word is 'may.'"

Barby wrote them down. "It all makes sense," she pointed out. "It could be, 'Seventeen may,' or 'come both.'"

"Keep going," Scotty urged. "Try another one."

The third group gave them a choice of "Cheyenne," which seemed unlikely, or "bad."

"He couldn't be talking about Cheyenne," Rick said. "The word must be 'bad.' That means the first figure of the pair is the null, because it's the second figure that stands for 'bad.'"

"Sounds reasonable," Scotty agreed. "Keep plugging."

So far, the probable words were: _Come both bad._

Page 276 in the fourth group turned out to be a table of atomic weights.

Line 86 was the element tantalum. If the first figure of the last pair was a.s.sumed to be a null, the word was the symbol for tantalum: "Ta."

Rick stared at it. "Something's wrong. This doesn't make sense."

Barby asked impatiently, "How do we know?"

Rick yielded and moved to the next group. It gave the word "rubles."

"That's Russian money," he said.

The trio looked at it in bewilderment, then Scotty suddenly let out a yell of laughter. "I've got it! Can't you see? 'Ta' and 'rubles' go together! 'Tarubles.' Troubles!"

Then they were all howling with joy. Leave it to Chahda to dream up something like that, Rick thought. So far, the message made sense. _Come both, bad troubles._

He turned the pages and counted feverishly. The sixth group gave "am,"

the seventh "in."

The eighth group gave the message an ominous tone.

_Come both. Bad troubles. Am in danger._

The scientists and Mrs. Brant were looking over Rick's shoulder now, too.

The ninth group stopped them for a moment because the pair of figures standing for the word was 14. If the figure 1 was a null, the word was "the." But there were more than 14 words in the line, and the 14th was "my."

Rick looked at the faces around him. "I think it's 'my' because he must have had a reason for using nulls. If I were making up the code, I'd use them because sometimes there are enough words in a line so you need two figures and sometimes not. But you always have to put down two figures so the groups will be even."

"Good thinking," Rick's father complimented him. "Go ahead on that basis. But hurry up. The suspense is awful."