"Listen! The bell. Someone's at the door." Nancy went downstairs to see who it was. The caller proved to be Salty.
"And how are ye, lass?" he asked with a smile. "Sorry I can't give ye any report about that fellow what crashed into ye. I been lookin' high an' low for his boat, but I ain't seen any part o' her."
"Thank you. You've been very helpful," Nancy said, then added, "Salty, I'm thinking of going to the Heath gardens by boat. Have you ever noticed a sort of tunnel there, leading from the beach?"
"Can't say I have," the clam digger replied. "Are you figurin' on lookin' for one?"
Nancy smiled as she said, "Perhaps some time when you're not busy-"
Salty suddenly slapped his thigh and chuckled. "Women!" he said. "They never come right out an' say what they want. Nancy, I'll meet you an' your friends at Campbell's Landing ten o'clock sharp tomorrow mornin', barrin' rain."
Nancy thanked him. "Another thing, Salty. I'd like to find out about Walter Heath's experiments. Are you sure you can't tell me more about them?"
The man shook his head. "I don't know a thing more. But maybe Sam Weatherby can help ye."
"The curio dealer?"
"Sam worked at the Heath factory before he went into business for himself. He knew Walt as well as anyone in town."
"Then I'll go to see Sam Weatherby!" Nancy said, grateful for the information.
Soon after Salty had gone down the street, Bess and George left for home, promising to be on hand the next morning. Nancy drove to Sam Weatherby's shop.
"Haven't seen you in a while," he greeted her cheerfully. "Did you bring that pearl and the shell I offered to buy?"
Nancy told him the pearl had been stolen.
"That's too bad," the man said sympathetically. "Well, maybe you'll find a bigger one."
"I hope so," Nancy said with a smile. "But right now I'm more interested in Walter Heath's experiments."
She told about the pile of crushed and broken whelk shells she had found at the pond. "The colors were so beautiful, I've been wondering if he was trying to make dye from them."
"You guessed right," Mr. Weatherby said, eyeing her intently. "So far as I know, Walt had no luck, but he kept working at it. And once he said to me, 'Sam, even if I don't succeed in making a fortune in dye, there's another treasure on my estate.' Then he winked and said, 'It's right in plain sight, too!'"
"What did he mean by that?" Nancy asked.
The dealer shrugged. "Who knows? Walt was like that-full of riddles and secrets. In one way his experimental work brought him luck."
"How?"
"He found a big pearl; at least, that's what he told me. Said he was going to present it to a young lady friend of his-a dancer."
Nancy blinked in astonishment at the revelation. Had he really given the pearl to Juliana? Or was it hidden in one of the cloister walls? And was that what someone was looking for?
Nancy thanked the curio dealer for his information and turned to leave. An object in the showcase caught her eye. Lying in a velvet-lined case was the antique charm from a man's watch chain that Daniel Hector had sold to Mr. Weatherby.
"Handsome, isn't it?" the jeweler remarked, taking the charm from its case. "An old English family design. A genuine heirloom."
Nancy admired the piece of jewelry. Mr. Weatherby also showed her a pair of earrings, a bracelet, and a brooch, all bearing the same design.
"Daniel Hector sold me this entire set," Mr. Weatherby revealed. "That lawyer is a hard customer, though. He argues for the last penny."
"Did he inherit these from English ancestors?" Nancy asked.
"That's what he said. Between you and me, I think he got them from a client who couldn't pay a bill."
Nancy wondered if Hector had received the charm and the other pieces of jewelry honestly, but kept quiet.
When Nancy reached home she learned that during her absence a call had come from Hopewell. Either she or her father was to get in touch with the man who had phoned.
"He was a detective," Hannah Gruen told her, "and he wouldn't give me a message."
Nancy called headquarters at Hopewell. The plainclothesman was out at the time but had left his report for her. The stranger he had shadowed the night before had driven to River Heights. From there he had gone to the abandoned Heath factory to meet another man.
"If I only knew who that person was!" Nancy exclaimed.
"I have a description of him," said the police sergeant and read it. Nancy was almost certain he was the same man who had damaged her motorboat! She thanked the officer, then hung up. The young detective mulled over what she had just heard.
Obviously the intruders at Heath Castle knew she was working on the case and had sent someone to shadow her. Would they stop there? Or was she in danger? Her father was out of town on business, so she could not discuss the matter with him. Finally she went to bed.
The next morning Nancy put the key to the front door of Heath Castle in a pocket of her slacks, then hastened to Campbell's Landing. She was the first to arrive and arranged to rent a motorboat. She was just getting it ready when George and Bess arrived. Finally Salty showed up in his rowboat, which he fastened securely to the larger craft, then jumped in with the girls.
"All set!" he announced. "Cast off!"
The girls enjoyed the ride upstream; not only because it was beautiful on the river, but because the clam digger entertained them with songs and stories of the sea.
Soon the girls saw the high turrets of Heath Castle in the distance. Nancy recalled the man she had seen signaling from one of them with a flashlight.
"His helper was probably waiting on the water," she thought.
The shoreline was matted thickly with bushes, and only a narrow beach was visible. Above it stood a high, weather-stained wall, the river barrier of Heath Castle.
"Let's anchor the motorboat in the river and take the little one ashore," Salty suggested. They untied the rowboat and climbed aboard. With powerful strokes the sailor sent it surging through the water. Presently it grounded on the shore and they stepped out.
The girls left Salty, who wanted to look for clams along the beach. The young sleuths turned their attention to the high wall which marked the rear boundary of the Heath estate. Only the treetops above the gardens were visible. Directly in front of the wall grew tall brier bushes.
Nancy and her friends walked along the beach.
"That boy who stole your clothes seemed to appear out of nowhere," Nancy said. "I didn't see him scale a wall. He must have reached the beach some other way."
"You mean by the cloister?" asked Bess.
"Maybe. I'm sure there's an opening along here."
Pushing ahead, she began to examine the base. Finally, parting some brier bushes, she saw several large stones which apparently never had been cemented into the wall. She pushed against the center one. It moved easily!
"Girls, this may be an entrance!" Nancy cried out.