"We can't just now," Nancy called. "Have a job to do."

"A mystery to solve?" asked one of the young men, coming to her side. He was Rick Larrabee, tall, very blond, and an excellent dancer. Nancy had enjoyed having dates with him during her stay at camp.

"A detective never tells her secrets," she said, laughing. "But I promise we'll all join you later."

"I'll hold you to that," Rick replied.

Nancy, Bess, and George quickly showered and changed their clothes. Then they set off in Nancy's convertible for Bridgeford. The old town, situated about a mile from the main road, was a beehive of activity.

"Oh, this is simply wonderful!" Bess cried out in delight, gazing around at the quaint buildings, some of which had been restored.

"I like that covered bridge," George spoke up. "I suppose it led to what was the main road in olden days."

"This rushing stream was used to turn the water wheel in that old mill," Nancy remarked. Some distance up the stream stood the miller's vine-covered cottage. The great wheel and the grinder were in a wing of the house.

The girls walked around for a while, inspecting the ancient bakery which as yet held no food; the blacksmith's shop with its fire pit, anvil, and smoke-stained walls; and finally what a workman told them had been the "artillery house."

"What does that mean?" Bess asked.

The man explained that it had once contained firearms-rifles, pistols, cannon, together with bullets, gunpowder, and other weapons for helping ward off unexpected attacks from enemies."

"You mean like Indians?" Bess inquired. The workman nodded.

As the girls walked off, Nancy said, "Perhaps we've done enough sight-seeing and should find the old stagecoach." She was about to ask another workman where it was when the girls saw John O'Brien coming toward them.

He smiled broadly. "I thought I saw you here," he said. "Let me show you around."

Nancy thanked him but said, "We're eager to look at the stagecoach."

John O'Brien told the visitors to follow him, and led the way to an old barn which had not yet been repaired. As he opened the creaking door, the man said, "There she is. I detached the horses. They're in another barn."

"May we inspect the stagecoach?" Nancy asked.

"Sure. Go ahead. But don't damage anything."

John O'Brien said he had an errand to do in another part of the village. When he finished he would be back. The young man strode off and instantly the girls began to investigate the ancient vehicle.

Nancy took the photograph of old Mr. Langstreet's stagecoach from her purse to compare it with this coach. She stood off at a short distance and surveyed the one in the barn, then stared at the picture. The design and size were identical!

A pleased smile came over her face. "Girls, it looks as if this might have been Great-uncle Abner's stagecoach!"

"Super!" said George. "Now let's find that clue!"

After a short conference, it was decided that George would search the driver's seat and the box under it. Nancy would examine the interior, while Bess investigated the "boot" at the rear. This was a great triangular leather sack attached to the back of the stagecoach to hold baggage.

There was complete silence for many minutes as the girls worked. George went over every inch of the driver's seat, removing the cushion and looking thoroughly in the leather-lined box beneath. She found nothing.

Nancy had no better luck inside. She had turned up and thoroughly examined under and around the cushions on the front and rear seats, and the one in the center. She had felt the padded walls and looked for any opening. Then she had dropped to her hands and knees for an examination of the floor. Finally she came to the conclusion that no clue was going to be found easily.

Just then Bess gave a loud squeal. George and Nancy jumped to the ground and ran to her side.

"Have you found the clue?" Nancy asked excitedly.

Bess had unbuckled the cover of the "boot" and inside had found a newspaper dated 1860. Quickly she laid it on the ground and carefully turned the pages, skimming through the various items and advertis.e.m.e.nts which might yield the clue for which they were hunting.

Finding nothing, she turned back to the first page and this time all the girls went over each article minutely. Still they found nothing to help them.

"Oh dear!" said Bess. "I thought sure I had solved the mystery!"

The newspaper was put back into the "boot" and the fastenings closed.

"If the clue is in this stagecoach, it's well concealed," Nancy remarked. "I wonder if we could possibly look inside the cushions and other hiding places."

At that moment John O'Brien returned. He seemed to be excited. "Come on with me, quick!" he exclaimed. "They're going to put the water wheel into operation. It hasn't turned in a hundred years!"

The three girls hurried along beside him up the towpath which led to the miller's home. There were a few sight-seers present, but the bulk of the audience was comprised of people working on the restoration.

Bess was swept toward the great water wheel

They crowded into the small cellar room which contained part of the sluiceway leading to the big wheel. The girls became separated from John O'Brien and were pushed against one of the wooden sides of the sluiceway.

"Everyone set?" called a man standing not far from Nancy. He had one hand on a great wooden lever which could divert the water to or from the great wheel.

"Guess we are!" came a reply.

The man pushed the lever with all his might. Instantly tumbling, gushing water rushed into the sluiceway, headed for the wheel's blades. At the same instant the crowd surged forward to watch.

An overeager man stumbled into Bess and knocked her off balance. Unable to steady herself, the astonished girl tumbled headlong into the sluiceway!

Bess cried out and tried to grab the wooden side, but the rushing water was too powerful. She was swept along toward the turning blades of the great water wheel!

CHAPTER III.

An Ominous Warning

WHEN Nancy and George realized what had happened to Bess, the two girls made a wild leap forward and grabbed for her in the sluiceway. Water spurted in all directions over the stunned onlookers, as Nancy and George managed to pull their chum to safety.

"You all right, young lady?" cried out the man who had turned the lever.

"Y-yes," Bess sputtered.

She was a bedraggled sight, with her hair and clothes hanging limp! "Please, let's go home," she said plaintively.

"Right away," Nancy replied.