The wail died away across Moaning Valley.

“That wasn’t the moan from the cave!” cried Pete.

“No,” Jupiter agreed. “That was a man!”

“In trouble,” added Bob. “Come on, fellows!”

The sound had come from the base of the mountain that stood between the valley and the ocean — Devil Mountain, so called because of its jagged twin peaks shaped like horns.

The boys raced across the valley to the foot of Devil Mountain, where a pile of newly fallen rocks lay strewn across the slope. Dust still filled the air.

“Help!” a voice called feebly.

Pete knelt down beside the grey-haired man who lay there, his leg twisted at a strange angle beneath the rocks, his face contorted with pain. “Just lie quietly,” Pete told him. “We’ll get you out of here right away.”

Pete stood up and looked at Jupiter. “I think his leg is broken. We’d better go for help quickly.”

The man on the ground was dressed in the old work clothes of a ranch hand. He gritted his teeth as he spoke.

“You boys go to The Crooked-Y ranch house. I work there. Tell Mr. Dalton to get some men out here.”

The boys looked at each other in dismay. Another accident for one of Mr. Dalton’s men! More trouble in Moaning Valley!

Pete had come to The Crooked-Y to spend a two-week vacation with Mr. and Mrs. Dalton, the new owners of the ranch. Jess Dalton, a famous rodeo rider who had worked with Mr. Crenshaw in several Western films, had decided to retire and buy a ranch with his life savings. The Daltons had barely started rebuilding the run-down ranch when the trouble began.

Moaning Valley, which had earned its strange name from ancient Indian legends and some violent events of old Spanish days, had begun to moan again — after fifty years of silence. As if this was not enough to scare the hired ranch hands, the accidents had started.

The first accident occurred while two of the ranch hands were riding through Moaning Valley at dusk one evening. They suddenly heard a strange moaning noise, and their horses bolted, throwing both men. One of the men broke his arm, and both returned to the ranch talking about how there was “something spooky in that valley”. Soon after, a herd of cattle stampeded for no apparent reason in the middle of the night. Then a ranch hand walking in the valley at dusk swore he had seen a giant shape emerge from El Diablo’s Cave at the base of Devil Mountain. Shortly after that, two hands disappeared without any explanation and, though the sheriff insisted that he had found them in nearby Santa Carla, many of the ranch hands had refused to believe him.

Pete hadn’t been at the ranch very long before he realised that the Daltons were extremely worried. Searches of the cave had revealed no explanation, and the sheriff could not pursue ghosts or legends. Both he and Mr. Dalton were sure there was some simple explanation, but so far no one had been able to find it. So Pete had hurriedly sent for Bob and Jupiter, explaining that there was a possible mystery for the Three Investigators to solve. The two boys had no trouble getting permission to come to the ranch, and the Daltons were glad to have them.

The Crooked-Y was located only ten miles from the modern holiday resort of Santa Carla, and less than a hundred miles north of Rocky Beach on the California coast. The countryside consisted of rugged mountains, deep valleys and canyons, with isolated coves along the Pacific coast. Bob’s parents and Jupiter’s aunt and uncle had thought it a fine idea for the boys to have a chance to see a real ranch and go riding, swimming and fishing.

But the boys were not riding or fishing or swimming; they were investigating the mystery of Moaning Valley. And that was how they had discovered the man who lay there on the ground, his leg caught beneath the pile of fallen rocks.

“It’s this jinxed valley, that’s what it is,” the man muttered in pain. “I never should have come here… That moaning, that’s what did it.”

“No, I don’t think so,” Jupiter said seriously. “I think the shock of the naval firing loosened some stones and the slide resulted. The side of Devil Mountain is very dry and quite steep.”

“It was that moaning!” the injured man insisted.

“We’d better get some help, fellows,” Pete said. “We can’t get those rocks off him alone.”

Just then a horse whinnied close by. The boys turned to see three men riding over the top of the valley towards them. One of the men led a riderless horse. The leading rider was Mr. Dalton himself.

“What are you boys doing here?” Mr. Dalton demanded as he dismounted. He was a tall, wiry man in a bright red shirt, faded blue jeans, and tooled, high-heeled western boots. His tanned, leathery face was lined with worry.

The boys explained how they had found the injured man.

“How do you feel, Cardigo?” Mr. Dalton asked, as he knelt down beside the ranch hand.

“I’ve got a broken leg,” mumbled the man, “and it’s this jinxed valley that did it. I’m getting out.”

“I think the firing of the guns loosened some rocks and started the slide,” Jupiter explained.

“Of course,” Mr. Dalton agreed. “That was it. Hold still now, Cardigo, and we’ll have you loose in a jiffy.”

Moments later they had removed the rocks from the injured man, and the two ranch hands had gone for the truck. They backed up to the rock-fall and carefully lifted Cardigo into the back. The truck drove off for the hospital in Santa Carla, and the three boys returned to their bikes.

It was completely dark by the time Bob, Pete and Jupiter rode up to the ranch house and parked their bikes. Altogether there were five ranch buildings: a bunkhouse for the hands, a large barn, a smaller barn, a cookhouse, and the main house. The main house was an old, two-storey, wood-beam and adobe structure surrounded by a deep, cool porch. The whole house was covered with the bright red flowers of trumpet vine, and the deep red blooms of bougainvillaea. Fenced corrals surrounded the entire group of buildings.

Men were gathered in small grounds around the cookhouse, obviously talking about the accident. Their voices were low, but their faces showed fear and anger.

The boys were about to go into the main house when a voice came out of the night — a deep, harsh voice.

“What have you boys been up to?”

On the porch something moved and the boys made out the small, wiry form and sharp, weather-lined face of Luke Hardin, the ranch foreman.

“Big place, this ranch,” Hardin said. “Get lost mighty easy.”

“We’re used to open country and mountains, Mr. Hardin,” Jupiter replied. “You don’t have to worry about us.”

The foreman took a step towards them. “I heard what you’ve been up to. Moanin’ Valley, that’s what. That place ain’t fit for youngsters, hear? You stay away from there!”

Before the boys could protest, the door of the ranch house opened and a small, peppery woman with grey hair and a deeply tanned face bustled out.

“Nonsense, Luke!” Mrs. Dalton snapped. “The boys aren’t children. They seem to have a heap more sense than you do.”

“Moanin’ Valley ain’t a good place,” Hardin said stubbornly.

“A grown man like you,” Mrs. Dalton exclaimed. “Afraid of a cave!”

“I ain’t afraid,” Hardin said slowly. “But I ain’t afraid to face facts, neither. I lived around here all my life. Even when I was a boy I heard about Moanin’ Valley. I never believed the stories then, but now I ain’t so sure.”

“Fiddlesticks! It’s just old superstition and you know it!” Mrs. Dalton said. Though she spoke bravely, Mrs. Dalton couldn’t quite hide the fact that she, too, was worried.

“What do you think causes the moaning, Mr. Hardin?” Jupiter asked the foreman.

The foreman squinted gravely at Jupiter. “Don’t know, boy. No one else does, either. We’ve looked, but no one’s found anything. Nothin’ we could see, that is.”