"Oh, I must meet my double!" Cecily cried excitedly. "It's exasperating that we can't find her or the iron bird. What do you think we should do next?" she asked Nancy.

The young sleuth said she had no solution except hard work, meaning that they would have to keep on searching around Pudding Stone Lodge.

Cecily was silent for a full minute before she remarked, "That other red-haired girl's actions have been so strange I'm sure she's very worried about something. I wish I could help her!"

Nancy confided the theory that she had expressed to Bess and George.

"Oh, dear!" Cecily exclaimed. "If that girl is a prisoner, and you didn't hear or see anything of her when you were in the lodge, she must be well hidden."

"I agree," Nancy replied. "Of course she might have been taken out of the house and been kept somewhere else until after I'd gone."

During the delicious steak supper, which Cecily and Nancy served, the girls continued to talk about the locket, the missing red-haired girl, and Pudding Stone Lodge.

When they finished eating, George declared she felt fine and again longed for action. Bess looked at her cousin sternly. "No physical exercise tonight. But I'll make a bargain with you. I'll drive you to the movies over at Ridgeton."

"Neat idea," said George. "I accept."

Bess turned to Nancy meaningfully. "I hope you girls don't mind not being invited. Somebody probably should be here to guard this cottage."

The significance of Bess's remark was not lost on Nancy. They must keep Cecily at the cottage so that she would surely be there when Niko camel

"How about a little walk?" Nancy asked Cecily.

"Oh, I don't believe so," the other girl answered. "I'd like to write some letters. My friends will wonder what has happened to me."

Nancy asked if Cecily minded if she went out by herself for a short time.

Cecily said, "Oh, go right ahead. I think I'll lock myself in, though, in case there are any prowlers around. When you return, knock three times."

Bess and George went off in the car, while Nancy strode along the lake front. Before she knew it, she had reached the path leading to Pudding Stone Lodge. On a sudden hunch Nancy decided to climb quietly up along the slope and pick up any dues she could. As she walked toward the house and looked upward, the young sleuth stopped short.

There was a steady glow of light from the bull's-eye window!

CHAPTER XII.

Precarious Hiding Place

THE light from the bull's-eye window began to flash on and off. Surely this must be a signal, Nancy thought.

She ducked behind a large bush and looked around uneasily. It occurred to her that a sudden light beamed on the grounds could reveal her hiding place. Nancy began to count the flashes to see if they spelled an SOS message. But they did not.

"I may be letting my imagination run away with me," she told herself. "It could be that the owner himself came back to find something in that room, and is poking a flashlight into various places. That would make it seem as if a light were going on and off."

Nancy's keen instinct told her, however, that this was not the right explanation. There were too many other suspicious and mysterious goings-on in connection with the Driscoll property! As she stood gazing, suddenly a light went on in the kitchen. Was someone getting a snack? Nancy decided to take a chance and move closer. She was too far below the kitchen windows to see anyone inside. But she did hear a door slam. Had someone gone to the cellar? Nancy listened for the person's return. After a time, when she heard nothing, she began to wonder if the Driscolls carried on some kind of work down there.

It occurred to Nancy that the signaling from the window might have been for someone waiting on the lake or in the woods-or, as she had guessed earlier, from a prisoner in the room. At that moment she heard a muffled humming sound.

"It's the same machine noise that I heard before!" Nancy thought.

She decided to try tracing it. Straining her ears, the young sleuth followed the sound down through the woods of the embankment. It was now bright moonlight and she had no trouble descending. As Nancy neared the beach, she was startled by a rustle of the brush behind her. She darted in back of a large tree, hoping no one was following. The rustling had stopped. There was complete silence now, except for the humming sound. Nancy took a chance and moved toward the beach. Suddenly she stopped, her heart beating faster. She noticed the silhouettes of two men standing not far from the water. Where had they come from?

Now the humming noise was louder. The girl detective was sure she was near its source. Nancy was greatly puzzled. What was the source of the sound?

Suddenly the men turned and walked directly toward Nancy. One of them was Vince Driscoll, the other a stranger, short, wiry, and partially bald.

Hastily Nancy retreated along the woods path. She looked back. The men had begun to climb the bluff. With a sigh of relief, Nancy paused. But the next moment the men stopped too. "She's here somewhere," said the stranger. "Karl saw her!"

Nancy tried to figure out who "she" might be. "Do they mean me, or the mysterious red-haired girl?"

Then she heard Vince say, "Come on. Let's look over here." Again they started in Nancy's direction.

Sure she was in danger, the young sleuth tiptoed away. But she stepped squarely on a dead branch, snapping it with a loud crack.

"What was that?" she heard Vince growl. "Somebody's ahead of us."

The men broke into a run, and Nancy had no choice but to run herself. Could she make her way to the cottage safely? A chilling thought struck her. The men might have a confederate searching the woods! She could be trapped!

Wondering what her best means of escape might be, Nancy decided on Henry Winch's dock. This was now not far away.

"I can lower myself under it and hang on," thought Nancy. "If necessary, I can even drop into the water."

As quietly as she could, Nancy continued running. But Vince and his companion evidently could hear her for they hurried in the same direction.

Nancy managed to reach Henry Winch's store. She dashed around the side which was in the shadow and let herself down underneath the dock. She clung to a supporting beam.

A minute later her pursuers stomped onto the dock. "I caught a glimpse of her," the stranger said. "She's got to be around here somewhere."

As Nancy's heart pounded, the two searchers circled the little building. She heard Vince say he would try the door and windows.

"They're locked!" he growled in disgust.

"Maybe she had a key. Why don't you bust in and find out?" the other man asked.

In a moment Nancy heard the tinkle of glass and the raising of a window sash. There was silence for several seconds, then Vince's voice. "She's not in here. You weren't seeing things, were you, Webby?"

"I sure wasn't," his companion answered angrily. "Hey! Maybe she's underneath this dock. Let's look."

Nancy had just decided that there was nothing left for her to do but drop underwater and hold her breath as long as she could, when a sharp whistle pierced the air from the direction of Pudding Stone Lodge.

"That's Karl!" Vince exclaimed. "Wonder what's up."

"We'd better go," Webby said.

To Nancy's intense relief, the two men rushed off. She lost no time in hoisting herself up from under the dock and watched the men run along the beach. To her astonishment, when they reached the bluff just below Pudding Stone Lodge, the two disappeared!

"Is there an exit to the beach from the cellar of the house?" Nancy thought excitedly. "Old houses often had secret passages to be used as hiding places in time of trouble."