"Right," agreed Frank. "And the only thing unusual here is this shelf setup. I'll bet it's actually the entrance to the secret room."
"All we have to do is find the opening mechanism," Joe declared.
Using their flashlights, the boys went over every inch of the shelves. These were nailed to a
backing of boards. The Hardys pulled and pushed, but nothing happened. Finally, on the bottom
shelf near the wall, Frank discovered a knot in the wood. In desperation, he pressed his thumb hard against the knot.
There was the hum of a motor, and, as smoothly as though it were moving on greased rails, the
middle section of shelves swung inward.
"The door to the secret room!" Frank exulted.
Quickly the boys slipped inside the room and shone their flashlights around. The first thing they noticed was the flooring-recently laid bricks. Frank snapped on a light switch beside the
entrance.
The boys blinked in the sudden glare of two high-watt bulbs suspended from the low ceiling.
The next instant both spotted a small, handprinting press.
"The counterfeiters' workshop!" they cried out On a wooden table at the rear of the room were a camera, etching tools, zinc plates, and a large pan with little compartments containing various colors of ink. At the edge of the table was a portable typewriter.
Frank picked up a piece of paper, rolled it into the machine, and typed a few lines. Pulling it out, he showed the paper to Joe.
"The machine used to type the warning note Dad got!" Joe exclaimed excitedly. "The counterfeiters must have thought he was on their trail."
"And look here!" exclaimed Frank, his voice tense. A small pile of twenty-dollar bills lay among the equipment. "They're fakes," he added, scrutinizing the bills. "They're the same as Chet's and Tony's."
Joe made another startling discovery. In one corner stood a bow, with the string loosened and
carefully wound around the handgrip. A quiver of three hunting arrows leaned against the wall
nearby.
Excitedly Joe pulled one out. "The same type that was fired at the girls," he observed. "This must belong to The Arrow!"
"Docker matches his description," Frank pointed out. "He easily could have colored his hair gray."
The Hardys were thrilled at the irrefutable evidence all around them, "Now we know why
Markel and Docker rigged the mill wheel-to give a warning signal when they're working in this
room!"
"Also, we have a good idea what was being sent to Peters in the envelopes-phony twenty-dollar bills!"
"Let's get Dad and Chief Collig here!" Joe urged, stuffing several of the counterfeits into a pocket.
As the boys turned to leave, the lights in the secret room went out. Frank and Joe froze. They realized the mill wheel had stopped turning.
"The signal!" Joe said grimly. "Someone is coming!"
CHAPTER XIX
Underground Chase
THE HARDYS knew this was the signal for them to get out of the secret room-and fasti As they
hurried into the cellar, the lights came on again. With hearts beating faster, they started for the stairway. But before the boys reached it, they heard the mill door being unlocked, then heavy
footsteps pounded overhead.
"Docker!" a man's voice called. "Markel! Where are you!"
The Hardys listened tensely, hoping for a chance to escape unseen. When they heard the man
cross the ground floor and go upstairs, Joe whispered, "Let's make a break for it!"
The boys dashed to the steps. They could see a crack of light beneath the closed door to the
kitchen.
Suddenly the light vanished, and the rumble of the mill wheel ceased.
The Hardys stopped in their tracks. "Somebody else is coming!" Frank muttered. "Probably Docker and Markel. We're trapped!"
Again the brothers heard the mill door open. Two men were talking loudly and angrily. Then
came the sound of footsteps clattering down the stairs to the first floor.
"Peters!" The boys recognized Docker's voice. "Where in blazes were you?"
Frank and Joe nudged each other. Victor Peters was in league with the gatehouse men!
"What do you mean? I told you I'd meet you here at eleven," snarled Peters.
"You must be nuts!" retorted Markel. "You called here an hour ago and said there was trouble and to meet you at the Parker Building."
Peters' tone grew menacing. "Something's fishy. I didn't phone. You know I'd use the two-way radio.
What's the matter with you guys, anyway?"
"Listen!" Markel snapped. "Somebody called here and said he was you. The voice did sound sort of fuzzy, but I didn't have a chance to ask questions-he hung up on me. I thought maybe
your radio had conked out."
The Hardys, crouched on the cellar stairs, could feel the increasing tension in the room above.
Docker growled, "Something funny is going on. Whoever phoned must be on to us, or suspect enough to want to get in here and snoop around."
"The Feds! We'll have to scram!" said Markel, with more than a trace of fear in his voice. "Come on!
Let's get moving!"
"Not so fast, Markel!" Docker barked. "We're not ditching the stuff we've made. We'll have a look around first-starting with the cellar."
The men strode into the kitchen. Below, Frank grabbed Joe. "No choice now. Into the secret room!"
Quickly the brothers ran back into the workshop. Frank pulled the door behind him and slid the heavy bolt into place.
Tensely the brothers pressed against the door as the three men came downstairs into the
basement.
Frank and Joe could hear them moving around, searching for signs of an intruder.
"I'd better check the rest of the mill," Docker said brusquely. "You two get the plates and the greenbacks. Go out through the tunnel, and I'll meet you at the other end. Well wait there for Blum to pay us off, then vamoose."
"We're in a fix, all right," Joe said under his breath. "What tunnel are they talking about?"
"And who's Blum?" Frank wondered.
The boys heard the hum of the motor that opened the secret door. But the bolt held it shut.
"The mechanism won't work!" Markel rasped.
"Maybe it's just stuck," said Peters.
The men began pounding on the wood.
"What's going on?" Docker demanded as he returned.
"We can't budge this tricky door you dreamed up," Peters complained.
"There's nothing wrong with the door, you blockheads!" Docker shouted. "Somebody's in the room!
Break down the door!"
In half a minute his order was followed by several sharp blows.
"Oh, great!" Joe groaned. "They're using axes!"
"We won't have long to figure a way out," Frank said wryly.
"Way out!" Joe scoffed. "There isn't any!" Frank's mind raced. "Hey! They said something about leaving through a tunnel! It must be in here."
Frantically the Hardys searched for another exit from the secret room. They crawled on the
floor, and pried up one brick after another looking for a ring that might open a trap door.
"Nothing!" Joe said desperately. All the while the men in the cellar kept battering away at the door. "Good thing that old lumber is such hard wood," Frank thought. "But they'll break through any minute." "Look!" Joe pointed.
"Under the bench!" Frank noticed a shovel lying beneath the work-table. The boys pushed it aside, and saw that the wall behind the table was partially covered with loose dirt. On a hunch Frank grabbed the shovel and dug into the dirt.
"This dirt might have been put here to hide the entrance to the tunnel!" he gasped.
"It better be!" His brother clawed frantically at the dirt.
At the same moment there was a loud splintering noise. The Hardys looked around. A large