Rick shook his head. "Not to me. But let's start from there, anyway.

Maybe the twelfth group of numbers has a clue."

He counted rapidly across the number groups. "That group is 4399693. Now what?"

Scotty suggested, "Subst.i.tute letters for the numbers. That would make it DCIIFIC. That doesn't mean anything."

"Maybe you counted the wrong way," Barby said thoughtfully. "Count down the columns instead of across."

Rick did so. "That's 8337373. Subst.i.tute and it comes out ... let's see ... HCCGCGC. Nothing there, either."

Scotty had a pad of paper and a pencil and was making idle doodles. "I'm trying to recall. When did Chahda learn anything about codes?"

Rick thought for a moment. "He never did, that I know of," he said finally.

Barby stood up. "Well, I'm going to shower and change before dinner,"

she announced. "But I'll keep thinking. I have an idea that talking about it won't help much. If Dad and Rick are right about his using a code we're sure to know, it must be staring us in the face and we're too blind to see it."

"Good idea," Rick agreed. "Let's break this up and each think about it.

If we each search our memories, maybe we'll come up with a clue."

Barby went upstairs and Scotty retired to his favorite seat on the porch. But Rick felt that he could think better on his feet. A glance at his watch told him he had over an hour and a half before dinner. He waved at Scotty and walked across the gra.s.s toward the gray stone laboratory buildings. Professor Weiss was in his office working on some mathematical theory he was developing. It was away over Rick's head. For a moment he thought of posing the problem to the little professor, then thought better of it and pa.s.sed by the lab on the south side. He skirted the woods and crossed Pirate's Field, so called because local legend said the famed woman pirate, Anne Bonney, had once landed there with her gang of cutthroats. He paused for a moment and studied the fused sand left by the terrific heat when the first moon rocket was launched, but the barren patch gave him no inspiration.

Staying on the sh.o.r.e path, he walked slowly toward the back of the island and presently came out at the tidal flats. The tide was out, leaving the rocks exposed. He sat down at the edge of the low bluff above the flats and stared into the patches of water.

It was a hard job, trying to recall every detail of his friendship with the little Hindu boy, but he tried. It had started in Bombay when Rick and Scotty were on their way to Tibet with Weiss and Zircon to set up the radar relay station for message transmission via the moon. When their equipment was stolen, it was Chahda who took the lead in finding it again. They had been amused by the beggar boy who had educated himself with an old copy of _The World Almanac_. His ability to quote anything from the "Alm-in-ack," as he called it, in English that was sometimes pretty funny, was really astonishing. Then, at the Lost City, he had more than proved his courage and loyalty, and the Spindrifters had sponsored his visit to America as a reward.

For a while Chahda had attended school in America, then he had gone to the Pacific with the Spindrift expedition to Kw.a.n.gara Island. After salvaging the remains of an ancient temple from one hundred fathoms of water--not to mention the treasure that was found--the Spindrifters had returned home. But Chahda had elected to remain in Hawaii with Professor Warren of the Pacific Ethnographic Society. Later, he had gone with the Warren scientific expedition to the South Seas, and Barby, Rick, and Scotty had joined the party in New Caledonia. After completing part of the expedition's work, the trawler _Tarpon_ had returned to New Caledonia where the young people had solved the mystery of _The Phantom Shark_. When the three Spindrifters returned home, Chahda had taken air pa.s.sage to Bombay to see his family.

"I can't remember all we talked about," Rick muttered to himself. "We talked about everything and anything. Except codes. I can't remember that we ever talked about codes."

He got up, noticing that the crew of builders were in their barge, returning to the mainland for the night. They were trucking materials to a point on the sh.o.r.e near Spindrift, using an old wood road, then taking the stuff the rest of the way by barge.

It was getting on to dinnertime. He took the woods path back, pa.s.sing by the new cottages. They were nearing completion, the outsides already finished. Beyond the cottages was the farm run by the Huggins family.

Mr. Huggins was just herding the island's milk cows into the barn for milking.

Rick kicked at a near-by tree. "Either I'm dumb or it isn't as simple as we think it ought to be," he said aloud, then went on into the house.

Scotty and Barby had done no better. They gathered at the family table with long faces and Barby placed the disturbing cable in the middle of the table as a centerpiece.

"If we look at it long enough, maybe we'll get inspiration," she said.

Professor Julius Weiss, the only one of the three staff scientists who was at home at the moment, picked up the cable and examined it.

"A cipher, eh?" He adjusted his gla.s.ses. "It certainly looks complicated."

"Any ideas?" Rick asked hopefully.

The little mathematician shook his head. "No, Rick. I could give you the cube root of the square of the sum of the numbers, or anything like that, but I'm afraid I wouldn't even know how to start breaking the code." He added, "John probably could. He had some experience with codes while in the Navy, I believe."

John was Professor John Gordon. He was on an extended trip to New Mexico, serving as a consultant to the Navy's guided missiles projects.

The third scientist, Professor Hobart Zircon, was giving a five-week series of lectures in nuclear physics at Yale.

"I'm afraid Professor Gordon is too far away to help us on this," Rick said.

Mrs. Brant came in, bringing a heavily laden dish of fresh corn on the cob. Behind her trotted a s.h.a.ggy little dog.

Rick snapped his fingers. "Here, Diz."

Dismal ran over and barked at his young master, then he rolled over on his back and played dead, his only trick. Rick grinned. "Did you bring him along as an adviser, Mom? I'll bet he'd be as good at solving this as any of us."

Mrs. Brant smiled. "From what your father told me, I think he might at that. But why all the long faces? I think it's exciting getting a code message from Chahda. Why, this is the first time we've had a code problem on the island since the moon rocket."

Mrs. Brant couldn't have caused a more sudden reaction had she tossed a lighted firecracker into the middle of the roast.

Barby knocked over her water gla.s.s.

Scotty gasped, "Great gra.s.shoppers! A book code!"

Rick strangled on a sip of milk, and when he could get his breath again, he ran around the table to his mother, kissed her soundly and lifted her hand high in token of victory. "The new champ," he proclaimed. "Mom, you're a genius!"

"But, Rick, I didn't say anything except...."

"You said just enough, dear," Hartson Brant replied. "We all had the answer right in that second, because you gave us a clue. Do you remember the code our former friend used when he was sending messages off the island?"

The "former friend" Hartson Brant referred to was a member of the staff who had turned renegade and helped Manfred Wessel's gang in their efforts to build a moon rocket, using the Spindrift design, in order to win the Stoneridge Grant of two million dollars. The traitor scientist had used code messages to keep the gang informed of new developments on Spindrift while he had used the cloak of false friendship to slow up the building of the Spindrift rocket.

"He used a double code," Rick explained. "Part of it was a regular cipher, but the first step was a book code."

"I do remember!" Mrs. Brant exclaimed. "He used a copy of that book Hartson's friend wrote. What was it? _Psychiatry Simplified._ The code was numbers that gave the page of the book, and the position of the word on the page, and unless you found the book, as Rick and Scotty did, you couldn't break the code!"

Barby jumped up in her excitement. "And I know what book Chahda was using!"

The rest of the group spoke as one. "_The World Almanac!_"

Scotty ran for the library, Rick on his heels.

"We told him about that code," Scotty said. "Now I remember when, too.

It was right after we got back from India, when we were showing him around the lab."

"I remember, too," Rick agreed. "We were telling him how the gang used my plane, with me flying it, to smuggle their coded messages, and he asked us about it because he had never heard of codes before!"

They reached the shelf that held the _Almanac_ and stopped short.

Because of the year-to-year news summaries in the famous annual, Hartson Brant had kept each edition as a reference source. There were over a dozen of them on the shelf.

"They're all different," Rick said. "The pages change each year. Which one did he use?"