Without mentioning that the key to the house had been lost and then recovered, Joe said they had found the answer to Collig's question at the bottom of Barmet Bay. The Chief looked at them hard. Then, muttering something about kids these days being awfully flip in their remarks, he went off.

"Now that we're on our own, let's hurry," Joe urged Frank, who was at the wheel.

Though the Mead mansion was not many miles from the center of Bayport, it seemed to the eager boys to be a long way off. They made the distance in good time, however, and pulled into the driveway. The grounds appeared to be deserted.

"Suppose we take different doors to work on," Joe Suggested. He happened to be carrying the key. "I'll go around to the bay side. You take the front door."

Joe hurried to the ornate door which faced the water, and surveyed its uniquely carved design critically. He felt sure that a keyhole was hidden somewhere in the carving. The Hardy boy began to inspect it closely.

He started at the right-hand side of the door, pushing at each ridge of the symmetrical design. His search yielded nothing. He tried the opposite side of the door, still without success.

74 "Guess I'll start at the very top and work down," Joe concluded. "This door just has has to to have a keyhole."

For half an hour he pushed and pulled, growing more puzzled each minute. Finally he tried combinations with both hands on sections of the raised design. Suddenly his efforts were rewarded. Two pieces of molding shifted. One of them revealed a keyhole!

Excitedly Joe tried to insert the key. His face clouded; it did not fit. The disappointment he felt lasted only a moment, however. Certain now that the other doors had keyholes in them, he raced toward the front of the house and broke his news to Frank.

The older boy, who had found nothing yet, became hopeful. Feverishly he once more went over the intricate design of the front door. The upper and lower halves of this door were outlined with a wide border, each of them containing an inset. At first glance the upper inset looked like a huge turtle. Joe, standing at a little distance, suddenly had an idea.

"Say, Frank, that turtle's appendages are almost like the strange Y we've been seeing so often lately!" he cried out.

Frank stepped back a few yards. "You're right," he said excitedly. "The two front feet and the right hind one do form sort of a Y. Wonder if there's any significance to it."

75 As Frank started his investigation again, he accidentally pressed the palm of his left hand against the arched back of the turtle. Suddenly the reptile's right hind foot moved to the side, revealing a large keyhole.

"Look!" Frank yelled. He took the key from Joe and inserted it into the keyhole. "It fits!"

he cried a moment later.

Holding his breath, he turned the key. A clicking sound! Since there was no k.n.o.b, Frank used the key to pull the heavy door toward him. It swung outward on hidden, noiseless hinges.

The two Hardy boys stepped over the threshold of the Mead mansion!

CHAPTER IX.

Joe Is Missing.

when the boys' eyes became accustomed to the dimness of the shuttered house, Frank and Joe gazed around. They were in a large entrance hall, heavily carpeted and richly furnished. The walls were solidly paneled in carved wood.

Slowly the brothers went from room to room, peering through the open doorways.

Library, living room, dining room-all were tastefully decorated. But the furniture was dark and ma.s.sive, producing a gloomy, weird effect.

"There's no light on down here," said Joe as they reached the kitchen. "If Mr. Mead, or whoever that man on the road was, left one burning, it wasn't on this floor."

"Who was was that man on the road?" Frank speculated. "Now that we know the key he had that man on the road?" Frank speculated. "Now that we know the key he had fits this house, it makes things more mysterious than ever."

"You're right," Joe agreed. Idly he touched an electric switch on the wall. The room suddenly was filled with light. Both boys jumped. "The current's on!" Joe cried out.

"But it isn't supposed to be!" Frank said. "There's something funny about this. Why would the power company leave the current turned on in a house that has been closed for five years?"

The boys did not speculate about this very long, because their attention was drawn to the doors and windows. There was not a sign of hardware on any of them. Locks, latches, bolts, hinges-all were ingeniously concealed.

"Let's look at the rest of the house," suggested Joe, snapping off the light.

Frank had become intrigued by the library with its huge fireplace and its hundreds of books. Since he wanted to pause and look at them, Joe said he would go upstairs alone to see if any lights were on.

"Locks and Keys, by John Mead," Frank read, taking down one of the volumes from a by John Mead," Frank read, taking down one of the volumes from a shelf.

A picture of the author in the front of the book did not look at all like the man the boys had met on the road. Frank decided the author must be the deceased owner of the house.

There was nothing in the volume which told how to install invisible hardware.

The Hardy boy found another book on the history of locks and keys, which looked so fascinating that 78 he turned on a reading lamp and sat down in an armchair to glance through the volume.

He became completely absorbed in the subject, learning first that in Biblical times keys were made of wood and were so heavy they had to be carried over one's shoulder; that later the makers of metal keys received the name of locksmith locksmith because actually they were because actually they were blacksmiths who forged keys; and that the invention of truly burglarproof locks is barely a who forged keys; and that the invention of truly burglarproof locks is barely a hundred years old. Frank was interrupted by a distant voice saying: "We'd better go now."

"All right, Joe. Just a minute," he called.

But the minute dragged into five, and might have been even longer, but for the fact that the lamplight suddenly went out.

Frank got up and went to the hall. He clicked on the switch, but this time the center light did not flash on.

"That's funny," the boy thought. "Main fuse must have blown out. Hey, Joe!" Frank called loudly up the dark stairway. "Joe!"

There was no reply. Frank concluded his brother must have gone outside. When he endeavored to open the front door, he discovered he did not know how. Playing his flashlight on the carved design, the Hardy boy finally figured out the reverse action of the turtle's body, and went outside.

Joe was not around the house, so Frank hurried to the roadster. His brother was not there, either.

79 After looking around the grounds, going as far as the waterfront, the youth decided that Joe must be inside the house, after all.

This was true, and besides, Joe was in difficulty. Not having found a light burning upstairs, he had paused in a den to look at some hunting trophies which hung on the walls.

Switching on a lamp, he gazed in admiration at several fine specimens of moose head, deer antlers and a buffalo head. In moving about, the boy accidentally closed the door leading into the hall. It locked!

"That was stupid of me," he muttered.

He had barely begun to look for the combination to open it, when the light went out.

Unfortunately he had no flashlight and could not see the design on the door well enough to work on it. Hurrying to one of the shuttered windows, through which rays of sunshine filtered, Joe lifted the sash.

"Well, that's a break," he thought.

Getting the shutters open was another matter. Though no fastener was visible, they were locked. Joe ran his fingers over the surface hunting for a secret spring, but he found none.

Next he took a penknife from his pocket and inserted one of its blades in the crack between the two shutters. Suddenly there was a click, and they opened.

Looking out, he saw his brother on the ground below him. "Hi, Frank!" he yelled.

The older boy looked up in amazement. "So that's where you are! I've been looking everywhere 80 for you. We'd better go home now or Aunt Gertrude will be furious. You know we promised to be home in time for dinner."

"I can't get out," said Joe.

"What do you mean?"

Joe leaned from the window and surveyed the wall of the house. There was no possible way for him to climb down, and the drop was too far to be made safely.

"The door to this room is locked!" he explained to Frank. "I'll try it again, though.

Suppose you come up and see if you can open it."

Frank re-entered the house and quickly found the door to the room where Joe was imprisoned. He played his flashlight over the panels, taking in every detail of the unique climbing vine pattern. There was no clue as to where the lock was hidden.

By this time the Hardy boys had learned there apparently were no rules to go by in opening the Mead doors. The hidden locks might be found almost anywhere. Frank pushed and pulled at each leaf of the design. Finally his efforts were rewarded. One of the leaves moved aside, revealing a small latch, which he lifted with his fingers, and the door opened.

"Whew! I'm glad to be out of that place," Joe said in relief. "What happened to the lights?" he asked.

"I don't know, unless a fuse blew out."

As Joe followed his brother from the house, he asked what Frank had found in the library.

"Some excellent books about locks and keys," was the reply. "One by John Mead. I'll tell you about them as we drive along."

Joe listened to Frank attentively, and made no comment until his brother said that he was sorry to have been interrupted in his reading. Joe inquired who had interrupted him.

"You."

"Me? How did I interrupt you?"

"When you said we'd better go."

Joe turned and stared at his brother. "I never said that," he replied in surprise.

It was Frank's turn to be puzzled. He was positive someone had said those words. Both boys concluded either that Frank had thought he heard someone speak, or else someone had been talking to another person in the house.

"But why didn't they let us know they were there?" asked Joe.

"Search me," Frank shrugged. "Say," he added, as a thought came to him, "maybe they turned out the lights."

Joe conceded that Frank's guess was a shrewd one. He could not figure out, however, why anyone who might have been there for a legitimate reason did not inquire what the boys were doing in the house. And if the persons had no right inside the place, why should one of them have spoken and given away his presence?

Frank, lost in thought, almost failed to stop at a 82 traffic light which changed rather abruptly, but he jammed on the brakes just in time to keep from crossing the intersection. Neither of the boys spoke as they waited for the signal.

Then, as it changed from red to yellow and then to green, Joe gave a yelp.

"It hums! It sings!" he cried out. "Maybe this is the light Doctor Lyall meant!"

CHAPTER X.

The First Break.

joe excitedly suggested that they start out at once and drive ten minutes in various directions to try to locate the place where Doctor Lyall had been taken -the place where they perhaps might find the wounded Lenny Stryker. Frank Hardy looked at his brother.

"I'm with you, if you can stand Aunt Gertrude's wrath," he laughed.

"It won't take long," Joe stated, adding, "We can't go east because of the bay. Let's save the direction toward town till last. We can look around there after dinner."

"Good idea," Frank agreed, turning the car toward the west. "Let's see what's down this road."

As a matter of fact, there was very little to see. It was a farming section, and there was nothing to indicate a crooks' hide-out. In exactly ten minutes, Frank stopped in front of a small house where a ferocious watchdog was tied up. Joe jumped out of the car and tried to get to the front porch. The un83 84 friendly dog would not allow this. He set up a terrific barking, which finally brought a man from the rear of the farmhouse.

"What do you want?" he asked gruffly.

Joe found it hard to explain why he and his brother had stopped, so he asked what breed the dog was. The farmer refused to answer, and again repeated his question. As the boy hesitated, the man said suddenly: "I don't like snoopy people. Get out of here or I'll set the dog on you!"

The Hardys were suspicious of him because of his manner, but at this moment the front door opened and a sweet but dejected-looking woman appeared with two small children.

She smiled wanly at Joe, then looked at the farmer.

"Please, Jonathan," she pleaded, "don't be so harsh. This boy hasn't done anything."

She looked at Joe. "Can I help you?" she asked.

The boy was sure this could not be the place to which Doctor Lyall had been taken. He mumbled some excuse about being interested in dogs, and asked the woman what kind hers was.

Before she could reply, the farmer ordered her into the house. In the next breath the angry man commanded the dog to spring on Joe. But the Hardy boy outguessed him and dodged just in time. The youth raced to the car and jumped in.

"That guy ought to be put in a cage with some lions!" Frank stormed, as he drove off.

85 "Lions with big teeth!" Joe panted.

The boys returned to the humming light intersection and then headed north. Five minutes later they pa.s.sed the Mead property and gazed intently into the grounds. There was not a sign of anyone about. In another five minutes they reached a tiny settlement which consisted of a general store, a garage, a church and a few houses. Frank stopped the car.

"A peaceful enough looking place," he remarked. "I wonder if we'll find a clue here."

The brothers decided to tackle Bilks' Garage first. Inside the barnlike building, a young man who did not appear to be very bright was washing a car. As a sudden thought came to Frank, he asked the youth whether he had changed a tire a few days before for a Mr. Mead.