They scrambled back up the mound, sinking in where the ground was soft from the recent rain, and climbed up to the top of the dam. It was six feet thick at the top, made of the same fitted rocks. But here there were holes and crevices, and the boys split up to search. Half an hour later, they all gave up.

“If the sword is in the dam,” Pete said grimly, “we’ll have to tear the dam down to find it.”

“Don Sebastian didn’t have time to make a fancy hiding place,” Bob reminded him. “I think we can say the sword isn’t in the dam, which means we’re at a dead end. We’ll have to find a brand-new clue.”

“Where, Bob?” asked Pete. “We’ve been all through those army documents, and Don Sebastian wrote only that one letter around then.”

“He was an important man, and he must have had many friends in the area,” Bob said. “Perhaps he got help from someone, or perhaps people saw him that day. We need to find something that can tell us more about what he did, maybe even something he said.”

“Gee,” Diego said doubtfully, “it’s been so long.”

“Yes, but back in those days, without the telephone, people wrote more letters and put more news in them,” Bob pointed out. “And lots of people kept diaries and journals. Maybe there was even a newspaper here then. I bet we can find some good stuff at — ”

“I know,” Pete moaned. “Back at the Historical Society! Gosh, detective work sure can get boring!”

Bob laughed. “Well, most of the old papers are likely to be in Spanish, so you’ll be spared reading them, Pete! But we might as well wait till tomorrow, when Jupiter can help. Besides, I haven’t done any homework yet this weekend.”

Pete moaned again. He’d forgotten all about his homework.

The boys started across the top of the dam towards the road and their bikes. Just as they walked off the dam, Pete stopped and stood alertly.

“Diego?” the tall boy said, staring off to the right, “does someone on your ranch own four big, black dogs?”

“Dogs?” Diego said. “No, I — ”

“I see them, Second,” Bob said, his voice uneasy.

The four big black dogs were some distance away, above the reservoir and beyond the burned area on the Alvaro side of the creek. They were pacing wildly in front of some trees and thick brush, their red tongues lolling out and their eyes glittering.

“Wow,” Bob said nervously, “they sure look mean, and — ”

A shrill whistle seemed to sound from nowhere. Pete whirled, and pointed back across the dam.

“That’s a signal! Run for those trees across the dam!”

In the distance, the four dogs raced towards the dam with their teeth bared and red tongues dripping! The boys tumbled back over the dam, and pounded across the rocky ground towards a line of old oaks some fifty yards away.

“It’s… too… far!” Bob panted.

“We… we’ll… never… make it!” Diego gasped.

“Faster, guys!” Pete urged.

“Pete!” Diego cried as he looked back. “They’re swimming!”

In their violent pursuit of their quarry, the four dogs had plunged straight into the small reservoir instead of circling it by the faster route across the dam! They were swimming strongly, and were soon out and leaping after the fleeing boys. But the delay had been just enough!

The three boys reached the twisted live-oaks, clambered wildly up, and sat on the heavy branches looking down at the four leaping, snarling dogs.

They were trapped!

The shrill whistle came again. The dogs stopped snarling and leaping, and lay down under the trees.

“Look!” Bob said. “Skinny and that ranch manager, Cody!”

Their thin enemy and the stocky cowboy were trotting across the dam. Skinny was grinning with delight at the sight of the boys high in the trees. When the two came up, Cody ordered the dogs back sharply. They lay at his heels, alert and quivering, as he looked up at the boys. His small eyes sparkled, and he smiled nastily at them.

“So we’ve got some trespassers, eh? These trees just happen to be on Norris land!”

“Your dogs chased us here, and you know it!” Diego cried.

“What were you and your dogs doing on Alvaro land!” Pete said hotly.

Cody laughed. “Now how you going to prove that, boy?”

“All I see,” Skinny said innocently, “is three trespassers up a tree on my dad’s land.”

“Like we told the sheriff,” Cody said with a smile, “We’ve been having trouble with trespassers.” He nodded towards the dirt road on the Norris side of the creek. A sheriff’s car was coming up it. “I guess he’ll believe us now.”

The sheriff’s car parked, and the sheriff himself got out with a deputy. They strode up to Skinny and Cody.

“What’s going on here?” the sheriff demanded.

“We’ve caught some trespassers, Sheriff,” Cody said. “The Alvaro kid and two buddies. I told you the Alvaros and their friends act like they think it’s still all their land! Running their horses on our land, breaking our fences, making illegal campfires. You know how bad a campfire is out here now.”

The sheriff looked up at the boys. “All right, you boys, climb down. Cody, hold those dogs back.”

The boys climbed down as Cody controlled the growling dogs. The sheriff looked closely at the two Investigators.

“I know you two, don’t I? Pete Crenshaw and Bob Andrews of The Three Investigators! From what Chief Reynolds has told me, you two should know better. Trespassing is a serious matter.”

“We weren’t trespassing, sir,” Bob said quietly. “We were on Alvaro land when those dogs chased us here.”

“Oh, sure.” Skinny sneered. “They’d have to lie, Sheriff.”

“You’re the liar, Skinny Norris!” Pete raged.

“Sheriff,” Bob went on, “if we were on Mr. Norris’s land when those dogs chased us, how come the dogs are soaking wet? It isn’t raining just now.”

“Wet?” The sheriff looked at the dogs.

“Yes,” Bob said firmly, “because they swam the reservoir to chase us, and that pond, and the whole creek above the dam, is on Alvaro land!”

Cody reddened and blustered. “You gonna listen to them kids, Sheriff? The dogs got wet earlier, yeah.”

“Well,” the sheriff said, looking hard at Cody, “those wet dogs make your story kind of shaky, Cody. I hope the evidence you got me out here to see is better.”

“It is,” Cody growled. “Come on, I’ve got it in my wagon down the road.”

“What evidence?” Bob asked as Cody and the sheriff walked away down the road.

“Wouldn’t you like to know!” Skinny sneered.

The boys and Skinny glared at each other as they waited under the oak trees for the sheriff. When he returned alone some fifteen minutes later, he was carrying a large brown paper bag. He nodded grimly to Diego and the Investigators.

“All right, you boys can go for now. I don’t know who’s telling the truth, but I’ve already warned Cody to keep his dogs on his own land, and now I’m warning you not to trespass.”

Diego and Pete opened their mouths to protest, but Bob spoke quickly first:

“Yes, sir, we’ll remember.”Then he added innocently, “Can you tell us what’s in that bag, sir?”

“That’s none of your business, Bob Andrews,” the sheriff snapped. “Now get out of here!”

Reluctantly, the three boys left. They circled the dogs warily, and went back across the dam to the road and their bikes. The rain began to fall heavily again as they rode down the Alvaro’s dirt road to the ruins of the hacienda a mile away.

As they passed the ruins, they saw Pico. He was walking slowly around among the burned rooms of the house as if searching for anything that might have been spared by the flames. “Find anything?” called Pete, as the boys rode up towards the burned-out hacienda.

Pico looked up, startled and then embarrassed. “I’m looking for the Cortes Sword,” he admitted. “It occurred to me that if Don Sebastian had hidden it, he might have hidden it in the hacienda. And with the house burned out, it might be revealed now. Metal does not burn in a wood fire, so the sword would be easy to find. But,” and he looked around at the skeletal walls remaining, “there is no sword here.” He kicked angrily at some roof tiles on the floor.