Ben was adding the chimney and woodstove to his drawing when Robert gave a low whistle, and said, “What is that?”
Ben followed the beam of Robert’s headlamp. A large round tube hung from the low ceiling, and it ran twenty or thirty feet to an enormous domed structure. More big tubes, at least ten of them, seemed to sprout from the top of the dome.
“We had one just like that in the basement at our house,” said Ben, “except about ten times smaller. Same thing, though. My dad called it an octopus furnace. This stuff we’re seeing? It’s all from different time periods—the woodstove probably came right after they stopped using the upstairs fireplaces. Then they burned coal under that big octopus dome. And look,” he added, aiming his headlight upward at the black metal pipes hanging from the ceiling beams, “those pipes come from the boiler, the newest heater. And the boiler sends hot water to all the radiators in the school.”
Pretending to yawn, Gerritt said, “Thank you, Professor Pratt. You can draw all the little maps you want, but this place gives me the creeps, and the sooner I’m out, the better! I don’t know about you guys, but I’m following those water pipes straight to where Tom said we should look for the entrance to the sub-basement—which is why we’re here, right?”
Ben wanted to keep exploring. He saw that there were actually four of the old iron woodstoves, each with its own chimney. But he tucked the drawing into his backpack and followed Robert toward the boilers.
Jill called softly from the north corner. “Hey—I found an opening!”
Ben hurried over and saw a boarded-up gap in the foundation, about four feet wide and three feet high.
Gerritt came too, and right away he said, “False alarm—see at the bottom there, the way those boards are slanted? I think that used to be a chute for dumping firewood or coal down here. And the boards here on the floor? Probably to keep the fuel from getting damp.”
Ben looked down. On either side of the chute’s opening, the floor was covered with wide oak planks that made a rectangle about fifteen feet wide and ten feet out from the wall.
Jill turned and started to walk toward the west wall, then suddenly stopped.
“Hey, something moved!” she whispered.
Gerritt grinned. “Probably just a big rat.”
“No,” she said, “I felt the floor move—under my feet. And listen . . . hear that?” She tapped her foot, first on one plank, then on its neighbor. The second plank had a hollow sound.
“Look!” Robert said. “A handle!”
Ben used his phone to snap a quick photo of the place Gerritt was pointing, and the flash practically blinded them. But they all saw a flat iron ring about four inches across, set into the thick oak floorboard so that it lay flush with the surface. It was caked with dirt and coal dust, almost invisible. Six inches in front of the ring, three of the wide boards were cut in a straight line. Ben walked along the center plank, the one with the handle, and about eight feet away, there was another straight cut across the same three boards.
Ben felt the boards move—Robert had already pried the handle loose, and using both hands, he was pulling upward.
Ben jumped to one side, and with a quiet groan from the hinges, Robert’s end of the hatch’s cover rose up until it was higher than his head. When he let go, the door stayed open, like one of those long lids on the bed of a pickup truck.
“Cool!” said Robert. “There’s a weight-and-pulley system—I could have lifted that thing with one hand!” Waving his arm like a cheesy magician, he smiled and said, “Ladies and gentlemen, this way down!”
CHAPTER 10
Below Below
A breath of even cooler air came flowing up into Ben’s face as he followed Robert and Jill down into the sub-basement. Blocks of gray granite had been stacked to make simple steps, twelve of them. Straight ahead at the bottom there was a small space—just enough room for the chains and pulleys that kept the door raised. He did a double take when he saw the weights—two large rusty cannonballs hung at the end of each chain. Ben tilted his head back and looked up at the hatch suspended above him. The bottom of the three wide oak planks had been sheathed with copper—the whole thing had to weigh several hundred pounds.
Robert said, “Better pull down that cover, don’t you think?”
Jill shook her head, and the beam of her headlamp whipped back and forth across Robert’s face. “No way!”
Robert shrugged. “Okay, but don’t blame me if Wally or Lyman comes and finds us.”
“I don’t care if the whole Glennley army shows up—that thing stays open!”
Ben said, “I agree with Jill. . . . I mean, who knows? We might need to get out in a hurry.”
That was not what she’d wanted to hear, and for a second Jill looked like she was going to bolt right back up the steps. But she turned around and followed Robert into the darkness.
Getting his bearings again, Ben realized that this wasn’t really the school’s sub-basement. Yes, the floor was lower than the level of the school basement, but looking to his right at the bottom of the stairs, an opening about three feet wide had been cut through the foundation of the north wall of the school. And beyond that, there was a completely different space, a cavern that had been dug into the earth below the north lawn—not underneath the school building at all.
As Ben stepped through the cut in the foundation wall, he could actually feel the space opening out in front of him—and he also imagined that he felt the weight of the earth above him. A quick burst of panic hit him, and he pictured the roof giving way, imagined those deadly tons of dirt and rock and trees crushing the air out of his lungs. And there’d be no way to call for help—no cell phone signal this far underground.
But swiveling his head around, the light quickly showed him that Captain Oakes and John Vining had not taken any chances. Every ten feet or so, a stack of sturdy granite blocks rose from floor to ceiling, and the floor down here was granite, wide paving slabs, most of them two or three feet square. The ceiling was high, at least ten feet, and it was solid, too—thick oak planks crisscrossing, and every place where the earth touched a plank, the wood had been covered with that same copper sheathing he’d noticed on the hatchway door. Ben smiled, and he remembered the name of the book they had found in the school library almost four weeks ago: A Man of the Sea, A School for the Ages. Everything the captain left behind had been built to endure.
All noise from the school had disappeared, but it wasn’t quiet. Ben heard the sound of water dripping and gurgling all around him. And there was no mistaking the smell: It was salt water.
There was another distinct odor that was harder for Ben to identify. He followed his nose, and his headlamp cleared up the mystery instantly—rotting wood, lots of it.
Ben snapped picture after picture. He wanted to document everything, wanted to be able to study the images later, back at his dad’s boat. Because centuries ago, workmen had built a system of elevated troughs and chutes down here, wooden channels to move the seawater around in this man-made cavern. Which made sense: If there really was a tide mill down here, the main ingredient was water.
The wooden support posts and the close-fitted planks were mostly rotted and fallen, but he could still get a sense of how they must have looked. They reminded him of the wooden structures he’d seen in photos of old mining camps in the Klondike, where streams had been diverted into wooden culverts to help the men wash away the gravel to find gold.
“Hey,” Jill called softly, “check it out—lanterns!”
Ben saw them too. About half of the granite foundation stacks had iron hooks driven between the blocks about six feet above the floor, and from each hook hung a square tin lamp. Through the sooty glass in the one closest to him, he saw the stub of a candle.
Walking directly to the east wall, Ben wasn’t surprised to see more granite blocks. Water trickled down the rock and pooled in a trough cut into the floor beside the wall. And he could see that the trough was slanted so the water would flow to the
left, which was north.
He turned around and walked straight back to the west wall. It was also made of granite blocks . . . except these were much larger, some of them as wide as four feet, and all were at least two feet thick. Moving closer with his headlamp, Ben saw that the top, bottom, and sides of each huge block had been carefully smoothed—the cracks between them were hardly thicker than a piece of paper.
And Ben suddenly understood why: The wooden chutes had carried the water into a reservoir behind this wall, and this was the dam, holding back the water so it could be released to run the tide mill—genius!
Grabbing his clipboard, he started to sketch how the water must have flowed, but a soft call from Robert stopped him.
“Hey, guys, I found the water wheel!”
Ben trotted over to the northwest corner of the space. Gerritt stood beside a wooden structure, kind of a shed. On the other side of the shed, almost touching the north foundation wall, he saw a rounded arc made of wood. He walked along the walls of the shed to his right until he could see around the far corner of the little building, and there it was—definitely a mill wheel.
He took a photo and then snapped more pictures as he walked eastward along the north wall. He was following the mill race, a channel about two feet wide and at least that deep, down below the floor level. The channel ended at the east wall, and he took a picture of the outlet, the place where the water would have flowed back into the ocean at low tide. The hole had been plugged with a big square granite block, sealed in place with something that looked like tar.
From back at the shed, Jill called out, “Robert, don’t go any farther—that floor’s rotten!”
“Hey, chill,” he said. “It’s not like I’m gonna drop into a mineshaft or something—the ground is only two feet down.”
“Well, you could still get hurt.”
Ben was beside her now, looking in at the doorway of the shed, and he agreed—the floor looked bad.
“See where the plank ends are nailed?” he said to Robert. “That’s where the floor joists are—they should be pretty solid.”
Robert wasn’t listening.
“After two tides spin, a man walks in. . . . After two tides spin, a man walks in. . . .”
Robert was muttering the clue over and over as he shined the light from his headlamp every which way inside the small structure.
Ben wanted to look more closely and also take pictures. He stepped up into the shed and felt the whole structure shift a little—not a good sign. But he got his footing on a solid spot, and took a good photo of the two millstones in the center of the shed. They weren’t big—less than two feet across. The wooden shafts and gears that had turned them had begun to rot, and a lot of the support structure had slipped to one side and collapsed into a jumble that looked like giant nursery blocks.
The more he looked around, the less sense it made to him. Why go to all this trouble to build such a tiny mill? And why hide it away like this?
He took a closer look at the millstones—they were totally black . . . and the floor all around the stones looked the same way, a deep, ground-in sooty color.
Ben reached down, rubbed the blackened floorboard, and then sniffed the smudge on his fingers . . . and the smell called up an image: the smoke from the cannons that were fired in front of town hall on the Fourth of July.
“That’s it!” he exclaimed. “That’s what Captain Oakes was doing down here—he was grinding, gunpowder! And he didn’t want King George to know about it!”
“Gunpowder?” said Jill. “You mean he could just make it? Right here? That is so cool!”
It was like Robert hadn’t even heard what Ben said.
“After two tides spin, a man walks in. . . . After two tides . . . Okay, so, like, I get the part about the spinning, right? That’s the wheel, and it spins after a high tide and a low tide—two tides. But ‘a man walks in’? A man walks in . . . what? Or, in where? That’s what we don’t know.”
Jill was still standing outside the shed.
“Well,” she said, “when you walk in, that means you’re going into something—some kind of a room or an enclosed space. And to get into a room, there’s usually a door. So, maybe it’s that one.”
And she pointed at a simple door on the wall to the left of the millstones, just four vertical boards with a couple of cross pieces, hanging on two rusty hinges. It was fastened shut with a bent nail.
Robert rolled his eyes. “Duh, Jill. That was the first place I looked.”
“Mind if I look too?” asked Ben.
“Knock yourself out, professor.”
Robert turned the nail and pulled the door open, and Ben looked through the opening with him, still being careful about where he stepped. They had a clear view of the inside structure that braced the water wheel.
“Hmm, what a surprise,” said Robert sarcastically, shining his light this way and that. “Dead end, same as the first time I looked. Any other bright ideas, Jill?”
Ben didn’t see anything unusual. “I guess this was just how they got at the inside of the wheel, to work on the spokes and the hub and stuff.” He didn’t want Jill to think he was making fun of her idea the way Gerritt had, so he added, “But we can take a really careful look at all the stone walls down here, maybe see if there’s a hidden door somewhere else. That makes sense, don’t you think?”
Robert was already out of the shed, doing just that.
Ben began snapping pictures of the water wheel. He loved the way it was put together, such simplicity and strength. And, really, the only parts of the wheel that were damaged were the bucket-like blades, the parts that had dipped down to catch the flowing water of the millrace. The hub was still solid, and so were all the spokes and the outer rim of the wheel. The thing had to weigh half a ton. It was nearly ten feet in diameter, from the bottom blades two feet below the floor level, to the topmost ones that almost scraped the ceiling.
And the workmanship was great. He focused in tightly on one of the broad spokes and snapped a picture of the wood, noticing the marks left by a tool—which had probably been held by John Vining himself. He snapped again and focused on a place closer to the outer rim, marveling at how tightly everything was joined together . . . and then he saw something, carefully carved into the oak—one word about an inch tall, just two letters: “in”!
And beside the word, a triangle—a pointer!
He leaned out into the center space of the wheel, holding on to the door frame of the shed. Using his headlamp beam, he slowly scanned the boards on the outer wall of the shed, as far as he could see on the left side of the doorway’s opening . . . nothing. Then he did it again on the right side. And this time he saw it, much harder to spot because the old pine boards of the shed were a lot darker than the oak of the wheel.
But there it was, the same word with the same pointer . . . except this pointer was aimed at the opposite direction!
“Hey, Jill, Robert! Come help me turn the big wheel!”
Robert snorted from twenty feet away. “Give it up, Pratt. Let’s get out of this dungeon.”
“Gerritt, I’m serious—I found something! Come look!”
The tone of Ben’s voice got both Jill and Robert to the doorway in seconds.
“See the words?” Ben said, aiming the beam of his headlamp. “ ‘In’! A man walks in! It has to be linked to the clue, so we’ve got to get these two pointers to line up!”
Robert said, “You stay here, and I’ll go see if I can move the wheel from the front—that should give me enough leverage.”
He went out of the shed and then around to the leading edge of the wheel, the part facing east. Ben could see his headlamp shining between the wheel and the side of the shed.
“Okay, here goes.”
Robert pulled down with his whole weight, and instantly the wheel spun smoothly, almost half a turn—the hub didn’t even squeak on the axle.
“Easy,” called Ben. “Too far. Bring it back up about a foot . . . slowly . . . a
little more . . . stop!”
The two pointers were lined up perfectly.
Jill whispered, “Do you see that?”
“I sure do,” said Ben.
There were actually two things staring them in the face.
First, with the pointers lined up, a square notch in the outer rim of the wheel lined up with a square post that was set into a granite block on the wall beyond. The post had an iron ring on its end, and when Ben pulled on the ring, the post slid out of the rock about eight inches, just far enough to fit into the matching notch on the wheel—which meant the wheel was now locked in place.
Gerritt was beside them again, and he saw the second thing instantly. “Check it out—that’s a walkway!”
And it was—sort of a short footbridge right through the wheel. With the water wheel locked in this exact position, an opening among the spokes lined up directly in front of the doorway from the shed, complete with boards to step on.
But the little path went nowhere. Beyond the outer edge of the wheel there was nothing but solid granite, the rough blocks of the northern foundation wall.
“You think it’s safe to walk on?” asked Jill.
Ben said, “Should be—here, hold on and give it a try.”
He held out a hand. She took it and then stepped out onto the boards. The wheel moved a little, but the square block locking it in place held tight.
“Feels pretty solid,” she said.
“Good,” said Ben, and he let go of her hand. He reached down and picked up a hefty piece of rounded oak, a tooth that had broken off one of the wooden millstone gears.
He passed it to Jill and said, “Give one of those granite blocks a good whack.”
She did, and then gasped as a wide slab of rock tipped toward her. Except it wasn’t rock—Ben knew that from the sound he’d heard when she’d hit it. It was a wooden panel, carved and painted to look like the rest of the wall!
He stepped forward and stood next to Jill.