They wandered back downstairs. In the long living room, a creak came from the wall near the chimney. Together, the boys stepped forward cautiously.

The mantel above the fireplace was dark wood, intricately carved with flowers and fat cherubs frozen in silent song. Underneath it, a pile of birch wood had been carefully arranged upon a pair of imp-shaped andirons. A squat ceramic vase filled with dead, colorless flowers was perched on the left side of the mantel. Eddie’s flashlight bounced off the mirror hanging on the wall above the hearth.

The vase crashed to the floor and Eddie jumped onto the nearest chair. His shout was interrupted by Harris’s apology.

“Sorry!” said Harris, standing next to the andirons. “My bag knocked it.” He bent down and examined the fireplace itself, carefully avoiding the shards of shattered ceramic. Crawling forward slowly, Harris stuck his head through the archway.

“What are you doing?” asked Eddie. He imagined hulking black dogs growling in the corners of the room. But this place wasn’t like the woods, Eddie told himself. This was only Nathaniel Olmstead’s house. There were no monsters here. Right?

“In Horror of the Changeling, Elise finds an envelope in the fireplace,” said Harris.

“Oh yeah,” said Eddie, leaning forward. He felt as if they were both peering into a gaping mouth. What if the fireplace decided to chomp? He frantically skittered backward, catching his coat sleeve on one of the andirons. Suddenly, the room shook. A loud scraping sound came from inside the chimney, like stone sliding against stone. Eddie yelped, thinking the house was about to collapse-but when he noticed Harris smiling by the glow of the flashlight, he realized that his friend had been right. The back wall of the fireplace had opened up. They had actually found a secret passage! How clever of Nathaniel. It was just like one of his books. Eddie had once thought these sorts of things existed only in books like Nathaniel’s.

“Nice job, Eddie,” said Harris as he quickly crawled all the way inside. The opening was about three and a half feet tall and nearly the same width. At the back of the fireplace, the tunnel bent like an elbow. Harris quickly disappeared around the corner. “You coming?” His voice echoed from the shadows.

Crawling on his hands and knees, Eddie felt the soot and grime clinging to his skin. The walls were made of large damp rocks. Moss grew in several places where water had seeped through the cracks. He followed the stone path past the andirons and to the right, where it stretched for a few feet before dropping off.

“Harris?” he called.

“Down here,” said Harris.

Eddie peered down to find a small ladder, about six feet high, bolted to the wall. At the bottom, Harris’s flashlight bobbed across a stone floor. Eddie gripped the cold metal rungs and lowered himself. The thought of Gertie crawling away from the Watchers at the end of The Witch’s Doom gave Eddie goose bumps, but he had to keep going.

Another archway greeted him at the bottom of the ladder. He ducked through it and followed Harris’s flashlight into a small cryptlike basement with a low ceiling. Spiderwebs draped from the rickety rafters like decaying curtains. Someone had piled a few boxes and stacks of newspapers along the walls. A dark, empty doorway gaped on each side of the room.

“Check it out!” said Harris from across the room. “It looks like some sort of… office or something.”

A desk with spindly legs sat along the far wall. Next to it stood a tall wooden filing cabinet. One drawer was open.

“Is this where he worked?” Eddie said, trying to calm his frazzled nerves. “How creepy.”

“Maybe this is just where he kept stuff he didn’t want anyone to find,” said Harris. He propped his flashlight on top of the filing cabinet, then reached inside the open drawer. He pulled out what appeared to be a hardcover notebook. He opened it. After looking it over for several seconds, he gasped. “Oh my gosh, Eddie, you have to see this!”

Eddie rushed over to the desk, and Harris showed him the notebook. On the first page, the words The Ghost in the Poet’s Mansion were written in scratchy penmanship. Underneath the title was the symbol Eddie had found in his copy of The Enigmatic Manuscript.

Harris flipped through the entire notebook, shaking his head. “It looks like a handwritten copy of a Nathaniel Olmstead book.”

“Someone wrote the whole thing out by hand?” said Eddie.

“That’s what it looks like. Just like The Enigmatic Manuscript. Only this one isn’t in code.”

Eddie glanced inside the open drawer. There were more notebooks, their spines facing up. He reached inside, took out another one, and opened the cover.

“Whoa,” Eddie whispered.

On the front page were the same scratchy handwriting and the weird symbol Harris had found in the other notebook, but this one was The Wrath of the Wendigo, Nathaniel Olmstead’s third book. Eddie put the notebook on the desk and picked up another one-The Revenge of the Nightmarys. And another-The Egyptian Game of the Dead. And another-The Cat, the Quill, and the Candle. “Are these notebooks all filled with his original stuff?”

“I guess so,” said Harris. He bent down and knocked on the stone floor.

“If he wrote these himself, they’re probably worth tons of money,” said Eddie.

Harris shook his head. “Yeah, but we’re not here for money.”

Eddie blushed. “I know that,” he said. He reached into his bag and pulled out The Enigmatic Manuscript. Opening the front cover, he compared the handwriting on the first page to one of the other handwritten books. “Look… Here, where it says Nathaniel Olmstead… you can see the writing is the same. The same person who wrote The Enigmatic Manuscript wrote these books.”

“So then it was Nathaniel who wrote them,” said Harris, glancing up from where he knelt on the stone floor.

“All clues point in that direction,” said Eddie. “This is his house, after all. But what does it mean? Why did he write all of his books by hand? And why did he keep them in this secret room?”

“Doesn’t look like this room was his only secret,” said Harris. “Look at this.” He ran his finger around the outer edge of the stone on which he was perched. “This one is different. There’s no mortar keeping it in place. Just like the one Gertie finds in The Witch’s Doom.” He blew at the crevice where the other stones met it. Dirt and dust flew from the crack. When Harris rapped his knuckles against it, the stone sounded hollow. “Help me out.” The two knelt down opposite each other, but after trying to lift the stone, they realized that it was stuck. Harris said, “Do you think there’s something down here we can use to pull it up?” He glanced around. “What about that hammer in your bag?”

Eddie laughed and unzipped his bag. He reached inside and handed the hammer to Harris. “Hammer one. Boomerang zero.”

“Very funny.” Harris jammed the claw side of the hammer into the space between the stones. He jimmied it back and forth. It wiggled a tiny bit, but it wouldn’t give. “Dammit,” he said.

Eddie stood up. “Didn’t Gertie use a crowbar in the book? Maybe that, along with the hammer, will do it?”

“If we can find one, sure,” said Harris.

They picked through a few boxes in each corner of the room. Eddie searched near the empty doorway and felt that the darkness seemed to stare at him. Icy air crawled across the floor toward him. Frustrated and scared, Eddie scrambled away from the doorway. “This place is giving me the creeps.”

“Really?” said Harris sarcastically, glancing up from another box. “Whatever for?” Then he let out a yelp, and Eddie nearly fell over. “I found it!” He knelt near one of the empty dark doorways on the other side of the room, holding a small crowbar over his head.