When the assistant librarian heard the boys’ latest request, he thought a moment. “A really early map of this area?” he said. “Yes, we do have one in our rare documents collection. One of the very first, from 1790. It’s so delicate we rarely bring it out into the light and show it.”

“Please, sir,” Bob urged, “may we look at it?”

The historian hesitated, and then nodded. He led them to the back where he unlocked a door. They all went into a windowless room which had its temperature and humidity kept at a constant level. All the documents were in glass cases or on shelves behind glass doors. The historian checked his files, then unlocked a drawer and drew out a long, flat glass case. Inside the case was a crude old map drawn in brown lines on thick, yellowed paper.

“Just look at it through the glass, please,” the historian said.

The boys bent over the ancient map of the Rocky Beach area.

“There,” Diego pointed in awe. “In Spanish: Condor Castle!”

“It’s there!” Bob exulted.

“Right on the Alvaro rancho, if that squiggly line is supposed to be Santa Inez Creek,” Diego said.

“What are we waiting for?” Pete cried.

The boys thanked the astonished historian, and ran out to their bikes.

The rain had stopped, but dark clouds still swept low over the mountains as the two Investigators and Diego rode along the dirt road of the Alvaro ranch. They were headed towards the old dam where they had battled the brush fire. As the road curved in alongside the dry arroyo and the ridge before the dam, Diego stopped.

“If I read the map right, Condor Castle is the rock peak at the end of this last ridge,” the slim boy said. “Santa Inez Creek is just on the other side of it.”

They left their bikes hidden in the brush beside the road, and pushed through the heavy chaparral to the edge of the deep arroyo. The dam was out of sight to their left, beyond the low, brush-covered mound that closed off the arroyo.

The boys looked across the arroyo and up at the top of the high ridge. At the left end of it, just before the ridge dropped sharply off to the low mound, the tall rock peak jutted up.

“That must be it!” Diego said again. “Right where the map showed it.”

“What’s it called now?” Pete asked as they scrambled down into the muddy arroyo and started up the ridge on the far side.

“Nothing, as far as I know,” Diego said.

The high ridge sloped in two sections: the lower two-thirds was a gentle slope covered with big boulders and brush; and the upper one-third was steeper and almost all rock with no brush. The boys were puffing when they climbed the last third and stood on top of the giant rock that crowned the long ridge.

“Condor Castle,” Bob said, awestruck.

From the great rock the whole countryside was visible except to the north, where the mountains towered towards the sky. But before the mountains rose, the boys could see the dam and the creek beyond with the charred brush on both sides.

“The creek’s swollen above the dam,” Diego pointed out, “and the dam’s already spilling a little. We’ll have a real creek below if it keeps on raining.”

Bob pointed down to the low mound at the base of the ridge. “Look how that mound separates the arroyo from the creek and the dam,” he said. “If the mound weren’t there, you’d have a second creek.”

The boys turned around and studied the rest of the view. To the west, they could see the road and the deep arroyo that reached south to the ruins of the hacienda almost a mile away. Directly to the south, more ridges fanned out. Far beyond them, the boys could make out Rocky Beach itself and the ocean, dark in the grey day. To the east, on the other side of the high ridge, Santa Inez Creek curved to the south-east. A trickle of water showed in it now. Across the creek bed, the fiat brush-land spread out, and they could see the Norris ranch houses and corrals a mile or so away. The road through the Norris ranch came up from the south to the dam and then disappeared north into the mountains.

“I wonder why they called this spot Condor Castle,” Pete said. “I don’t see any condors.”

“Just as well,” said Bob with a chuckle. “A condor is a kind of vulture!”

“Maybe,” guessed Diego, “the name comes from the bird’s-eye view up here.”

“Probably,” said Bob. “But let’s not worry about the name. We’re here to look for the Cortes Sword! Where do you think Don Sebastian hid it?”

“There must be a hiding place up here,” answered Pete. “A hollow somewhere, a crack in the rock, maybe even a cave. Let’s search, fellows!”

They spread out over the whole top of the rock, but quickly saw there wasn’t a hollow or crevice in it. The top was almost as smooth as marble. They stamped on every inch of it, and felt along the sheer sides as far down as they could reach. The rock was completely solid.

“Nobody hid anything in this rock!” said Pete. “Let’s try below it, on the sides of the ridge.”

Bob nodded. “Okay, Pete, why don’t you take the creek side, and Diego and I will go down the arroyo side.”

The boys scrambled off the peak and began to search again. Above the now trickling creek, Pete worked his way down the slope, making wider and wider sweeps. He found some loose boulders, but no cracks or hollows, no safe place to hide a sword.

Finally Pete gave up and walked around the north end of the ridge to find the others. Bob and Diego were almost finished searching on their side.

“There just isn’t any hole or crack to hide anything in, Second,” Bob complained.

Diego added, “Maybe Don Sebastian buried the sword.”

“Don’t say that!” Pete groaned. “We’d have to dig up the whole ridge. It’d take us forever!”

“I don’t think Don Sebastian buried it, Diego,” Bob said slowly. “If Jupiter’s theory is right — if Don Sebastian escaped successfully and went to hide the sword — he didn’t have a lot of time to work in. Put yourself in his place. He knew he was in danger and might not come back to dig up the sword himself, he knew that Jose might not return for years, and he knew that Sergeant Brewster and his pals were probably close behind him. If he buried the sword, he’d have to mark the spot clearly for Jose, or else the sword might never be found. But if he did mark the spot, Sergeant Brewster could see the sign, too, and guess what it meant.”

Bob shook his head. “No, I’m sure Don Sebastian wouldn’t have buried the sword. He would have hidden it somewhere near Condor Castle — someplace that Jose would be sure to think of. A place he wouldn’t have to take time to get ready, and wouldn’t have to mark.”

“But,” Pete said, looking all around, “where?”

“Well, we’re pretty sure the sword isn’t on this high ridge by Condor Castle,” said Bob. “So think of the rock as only a landmark, a clue to the general area. There must have been someplace nearby that Don Sebastian and Jose often went to, Diego, is there anywhere — ”

“The dam, maybe?” Diego suggested. “It was here then.”

“The dam?” Bob said. “Why not?”

Diego led them along the side of the ridge and across the low mound at its end. The mound ran up to the left corner of the dam. Water was spilling over the dam’s centre gate in a narrow stream, falling thirty feet to the creek bed below. The boys scrambled down the mound and dropped into the creek bed, heedless of wet feet. They examined the whole face of the dam as high as they could reach. It was built of hundreds — maybe thousands — of small boulders, fitted together and caulked with some kind of limestone mortar. There were no loose rocks, holes, or crevices.

“Solid as steel,” Pete said.

“My family had it built by local Indians almost two hundred years ago,” said Diego.

“Well, they sure didn’t leave any cracks to hide a sword in,” Bob said, “at least down here at the bottom. If there are cracks further up, you’d need a ladder to reach them, and Don Sebastian probably didn’t have a ladder. But let’s try the top.”