"Which dock?" the man rasped.

"It was just at the edge of Riverview. Dock Fourteen."

"At least you remember the number!" he snapped. "If I fail to find the gem, I'll come back here and make you pay! You may be certain of that!"

"I hope you do come back and that the police are waiting at the gate!"

Rhoda retorted. "I hope they put you in prison for the rest of your life!"

Picking up the lantern, Jay Highland started toward the stairway where Penny crouched. She moved hurriedly behind the door which opened into the crypt.

Slight as was the sound she made, Highland detected it.

"Who is there?" he called, holding his lantern high. "Answer or I'll shoot!"

Penny did not doubt that the man would carry out his threat. Her hand closed on a stone which lay on a ledge directly behind her.

"Don't shoot," she said, exposing herself to view.

"So it's you again!" hissed Highland. "I might have known!"

Penny let fly the stone. It struck the lantern. The light went out and oil and flame splattered over the stone floor.

Knowing it was her only chance to escape, Penny made a wild dash up the stairs. But she could not climb swiftly enough.

Jay Highland pounded hard after her. As she neared the top of the circular steps, he seized her arm and pulled her backwards.

Penny fought like a tiger to free herself. Together they stumbled and rolled down the wide stones to the floor of the crypt. There the man pressed his revolver hard into the girl's ribs, and she knew the game was up.

"Get in there!" he said, giving her a hard push. "This time you'll stay!"

As Penny reeled backwards into a wall, she heard the door of the crypt close and lock. With despair she realized that she too was a prisoner in the chamber of the dead.

CHAPTER 24 _CHAMBER OF THE DEAD_

Furious at herself because she had been so careless, Penny quickly tested the door. Finding it securely fastened as she had known it would be, she reached for her flashlight. It was missing from her pocket.

Though she groped about in the darkness, she could not find it. Giving up, she next turned her attention to Rhoda Hawthorne.

Thongs about the girl's wrists and ankles had been loosely tied. In a minute, Penny had set her free.

"Now to find a way out of here!" she exclaimed. "Highland and Winkey probably are driving to the river dock by this time!"

"It's no use trying to get out," Rhoda said despairingly as she rubbed her bruised wrists. "I'm sure this door is the only exit. Look in the adjoining room and you'll see what I mean."

Even as Penny started for the inner doorway, she heard a low moan of pain from someone imprisoned there.

"Who is it?" she asked tensely.

"I don't know," Rhoda admitted, huddling close beside Penny. "Two men, one of them in frightful condition."

"Can't we set them free? Rhoda, try to find my flashlight. It fell somewhere near the stairway."

While Rhoda groped for the flashlight, Penny entered the inner prison room. Not until she was very close could she see two men who were chained to a supporting pillar. Gags covered the mouths of both victims.

Penny untied the cloths. The first man she thus freed was someone she never before had seen. But as she jerked the gag from the lips of the second prisoner, she was startled to recognize Mr. Ayling.

"You!" she exclaimed.

"In the flesh, or what's left of it," the investigator attempted to banter. "Nice fix for an investigator, eh? The company probably will give me a merit award for this!"

"How were you enticed here?"

"It's a long story," sighed Mr. Ayling. "I've not been chained here long, fortunately. My companion, Joseph Merkill, is in much worse shape. He's been here a couple of days."

"I'll set him free first," Penny offered. She groped along the chains which fastened the man to the stone column. "Handcuffs? How can I get them off?"

"You can't, without a key," replied Mr. Ayling. "You'll have to go for help, or if there's no escape, wait until someone finds us here."

"That may not be before morning! Even if police should come here tonight, they might not see the stairway to the crypt."

"Any chance to break down the door?"

"I doubt it. Rhoda and I can try though."

"Rhoda Hawthorne! So it was her voice I heard! She and her grandmother are imprisoned also?"

"Yes, Rhoda's with me. Her grandmother, seriously ill, is locked in a bedroom upstairs. Who is Mr. Merkill?"

"His wife is an inmate here," the investigator explained. "Jay Highland--I know now he's a notorious jewel thief--induced Mrs. Merkill to come to the monastery. After he fleeced her of a diamond necklace, she smuggled a note out, telling how she was being mistreated. Her husband, from whom she had been estranged, decided to investigate. He came here alone. Discovering what was going on, he threatened to expose Highland to the police."

"Highland tricked me," Mr. Merkill added. "He promised I could take my former wife away and he would close the monastery. To show there were no hard feelings, he suggested we have coffee together. I drank it and became so sleepy I had to go to bed. That's all I remember until I woke up here, chained to a post!"

"I should have been more suspicious of Highland the first time I met him," Mr. Ayling blamed himself.

"Why did you go to Chicago?" Penny asked as she worked at the chains.

"I know now it was Highland who sent me the fake telegram. He wanted to get me away from here. While in Chicago, I contacted my home office and obtained information which convinced me Highland was a gem thief. So I came here, intending to demand a police investigation."

"I met one train," said Penny. "You weren't on it."

"I didn't arrive until early tonight. When the train came in, Winkey and Mr. Highland were waiting at the station."

"For you, obviously?"

"Yes, they told me Mrs. Hawthorne was at the monastery, seriously sick and wanted to see me at once. The story fitted with my own conclusion that despite Highland's previous statements, Mrs. Hawthorne was here. So I foolishly agreed to accompany them."