“This would probably be Sergeant Brewster,” Jupiter said grimly. “A pistol, and good boots.” He shook his head. “No wonder the three soldiers never came back!”

“They didn’t desert very far, did they?” Pete said.

“Three greedy guys looking for an easy fortune,” Bob added.

“But,” Diego asked, “where is my great-great-grandfather?”

Bob shone his light all around the cavern. From where they stood the boys saw nothing else. There seemed to be no hiding places in the sheer walls.

“Someone shot those three,” Pete said. “If it wasn’t Don Sebastian, who was it? Or did Don Sebastian just leave the cave?”

“It’s possible, Second,” Jupiter said thoughtfully. “But if he’d got all three of the soldiers, why wouldn’t he just bury them and stay hidden here?”

“Maybe it wasn’t Don Sebastian who shot them,” Pete said. “I mean, three against one, and they were trained soldiers. Maybe there were others, and Don Sebastian didn’t want — ”

“It was Don Sebastian,” Bob said. “Look over there! Way at the far end of the cave! There’s another passage, and something’s in it!”

When the boys reached the far wall, they saw that there wasn’t a passage after all, but only a low cul-de-sac that went back in some five feet. Inside the cavity, where anyone would have been hidden from immediate view, was the fourth skeleton. It was leaning against one of the few loose boulders in the cave. The remnants of clothing were different this time. Silver conchos of Indian design lay near the skeleton, and by it were two rusted old rifles. Diego picked up a concho.

“It is of our local make,” he said sadly. “I think we know now why my great-great-grandfather was never seen again. All these years he has been buried in this cave.

Jupiter nodded. “We were right all along. Don Sebastian planned to hide here. That’s why he put ‘Condor Castle’ on the letter to Jose, to tell his son where he would be. He escaped from Brewster and his buddies, got his sword from the line shack, and came up here to the cave. But the soldiers followed him, and they shot it out in here. Don Sebastian had the advantage of knowing the lay-out of the cave. Hiding in this cul-de-sac, he could pick off the soldiers as they crawled through the narrow passage. He got all three of them, but they got him, too. Some time later an earthquake buried the cave, and no one ever knew what had happened to the four men.”

“But, Jupe,” said Bob, “why didn’t Don Sebastian’s friends come here looking for him? They knew the eagle had found a nest.”

Jupiter shrugged. “We’ll never know. Perhaps they didn’t know exactly where he was and were awaiting further word. Or perhaps the earthquake covered the cave before they could get here. And apparently the friends were all killed or scattered in the fighting that soon broke out. By the time Jose got home after the war, there was no one to tell him that Sergeant Brewster’s report of Don Sebastian’s death wasn’t true. Jose might not have believed that the sword fell into the ocean with his father — but he’d then assume it was simply stolen.”

“Jupe!” Pete cried. “The Cortes Sword! It should be right here with Don Sebastian!”

They quickly searched the small cul-de-sac. Then they looked at each other in dismay.

There was no sword!

“Maybe,” Bob said, “Don Sebastian hid the sword in the cave.”

“In case something did happen to him,” Diego added. “He must have known those soldiers were close behind him. The Cortes Sword was a symbol of our family as well as a treasure. He would have tried to protect the sword and save it for Jose.”

“Let’s search!” Pete cried.

With only the one torch the boys couldn’t split up, so the search was slow work. Slow and useless. The cave was large, but there was almost no place to hide even a pin. The boys found one more little cul-de-sac and a few shallow crevices in the solid rock walls, but that was all. There were no holes in the solid stone floor, no debris to hide it under, and no place to dig and bury a sword.

“With Brewster and his cohorts close behind him, maybe on their way into the cave, I don’t think Don Sebastian would have had time to hide the sword even if there were a good place,” Jupiter said unhappily. “No, it looks as if he didn’t have the sword with him in this cave, fellows.”

“Then where is it?” Pete asked. “We’re no further along than when we started!”

Bob glumly agreed. “We’ve just about proven everything we guessed was true, but we still don’t have any clue to where the sword is.”

“I… I was so sure we were close to the answer,” Jupiter said slowly. “We must be missing something! Think about what — ”

“Jupiter?” Diego said, frowning. “If Don Sebastian wrote ‘Condor Castle’ on his letter to Jose, he knew Jose would come here to find him someday, right?”

“Yes, I suppose he expected still to be hiding here when Jose finally returned.”

“But Don Sebastian got shot here instead. Now, if he didn’t die right away but thought that he was dying, he’d worry about how Jose could ever find the sword. So — ”

“So he would have left some message for Jose!” Jupiter cried. “Of course! He would have been sure to try! Only after all this time would a message still be readable?”

“Depends what he wrote it on and with,” Pete said. “If he wrote a message. I didn’t see anything while we were looking.”

“No,” Diego admitted, “but we weren’t looking for anything like a message.”

“What could he have written a message with, anyway?” asked Bob. “I don’t think he’d have had paper and ink with him. Not if he was on the run.”

“I guess not,” said Diego. “But maybe he would have written it with what he had, fellows — blood!”

“On what?” Pete said doubtfully. “If he wrote it on his shirt or something, it’s long gone.”

“The walls?” Bob suggested, looking around.

“Badly wounded, dying,” Jupiter mused. “He couldn’t have moved much. Look on the walls of that little cul-de-sac!”

They all bent low and studied the rock walls of the cavity where Don Sebastian died. His skeleton seemed to watch them from where it lay against the small boulder.

“I don’t see anything,” Pete said at last, staying as far from the silent skeleton as he could.

“Would blood last so long, First?” Bob wondered.

“I’m not sure,” Jupiter confessed. “Maybe not.”

“What’s this?” Diego asked.

Near the skeleton, behind the small boulder, Diego picked up a small object that the boys hadn’t seen before. It was an earthenware jug with a broken top. It looked like Indian pottery.

“It’s got something at the bottom,” Diego said. “Sort of black and hard.”

Jupiter took the jug. “It’s an Indian pot, all right. That black stuff looks like dried-up paint.”

“Black paint?” Bob said.

They all looked at the pot, and then at each other.

“If he wrote something with black paint,” Pete said. “It could have faded, been covered by dust, and become almost invisible!”

“Everyone dust off the walls,” Jupiter said, pulling out his handkerchief. “And dust carefully! We don’t want to knock off any flakes of paint!”

Working gently, they all dusted the walls of the cul-de-sac. It was Pete who finally found the faint marks.

“Bob! Shine your torch right over here!”

Four words stood out faintly on the stone wall to the left of the skeleton. Spanish words, Diego translated them aloud.

“Ashes… Dust… Rain… Ocean.”

Everyone stared at the four words, wondering what they meant.

“The last two words are written pretty close together,” Diego commented. “They’re all very shaky.”

“Maybe,” Pete guessed, “he hid the sword in some fireplace somewhere?”

“Somewhere near the ocean?” Bob added.

“But how does ‘rain’ fit in?” Diego wondered.