Each was painted larger than life. On the far left was a thin, cruel-looking man with dark hair. He held a dagger that was almost hidden in his sleeve. Faded black letters at his feet read L. CAHILL. Next to him stood a young lady with short blond hair and intelligent eyes. She held an old-fashioned mechanism with bronze gears — like a navigation instrument or a clock. The inscription under the hem of her brown dress read K. CAHILL. To her right was a huge dude with a thick neck and bushy eyebrows.

He had a sword at his side. His jaw and his fists were clenched, like he was getting ready to slam his head into a brick wall. The inscription read T. CAHILL. Finally, on the far right, was a woman in a gold dress. Her red hair was gathered in a braid over one shoulder. She held a small harp — like one of those Irish harps Dan had seen in the Saint Patrick’s Day parade back home in Boston. Her inscription read J. CAHILL.

Dan got the strangest feeling all four were watching him. They seemed angry, like he’d just interrupted them in the middle of a fight… but that was stupid. How could he tell that just from a wall painting?

"Who are they?" Nellie asked.

Amy touched the figure of L. Cahill, the man with the knife. "L … for Lucian?"

"Yeah," Dan said. He wasn’t sure how, but he knew immediately that Amy was right. It was like he could read the expressions of the painted figures, the way he could sometimes do with Amy. "Lucian branch. That guy was the first."

"And K. Cahill …" Amy moved to the lady with the mechanical device. "Maybe K stood for Katrina or Katherine? Like Ekaterina branch?"

"Maybe." Dan looked at the guy with the sword. "Then T for Tomas? Hey, he looks like the Holts."

The picture of T. Cahill seemed to glare at him. Dan could totally see him in a purple running suit. Then Dan turned his attention to the last picture — the lady with the harp. "And… J for Janus. You think her name was Jane?"

Amy nodded. "Could be. The first of the Janus. Look, she’s got — "

"Jonah Wizard’s eyes," Dan said. The resemblance was eerie.

"These four," Amy said. "They look almost like — "

"Brothers and sisters," Dan said. It wasn’t just their similar features. It was their postures, their expressions. Dan had been in enough fights with Amy to recognize the look: These guys were siblings who’d spent years annoying each other. The way they were standing — like they knew each other intimately but were also trying really hard not to throttle each other.

"Something must’ve happened between them," Amy said. "Something …"

Her eyes widened. She moved to the middle of the mural and brushed away some cobwebs between K. and T. Cahill. There, small but clear on the painted horizon, was a burning house and a dark figure running away from it — someone shrouded in a black cloak.

"A fire." Amy clutched her jade necklace. "Like Grace’s mansion. Like what happened to our parents. We haven’t changed in all these centuries. We’re still trying to destroy each other."

Dan ran his fingers across the mural. It made no sense that they could know who these people were, but he was sure Amy was right. He just knew it, somewhere inside.

He was looking at four siblings — the beginnings of the Cahill branches. He studied their faces the way he used to do with his parents’ photograph, wondering who he resembled most.

"But what happened?" Nellie said. "What was in that house?"

Dan turned toward the stone pedestal. "I don’t know, but I’m thinking it’s time to open that vase."

Dan volunteered. Amy and Nellie stood back as he slowly lifted the vase off the pedestal. No poison arrows flew out. No spikes shot from the ceiling and no snake pits opened up, which Dan found kind of disappointing.

He was about to open the lid when Amy said, "Wait."

She pointed to the base of the pedestal. Dan had noticed the carvings, but he hadn’t realized exactly what they were.

"Is that… sheet music?" he asked. Amy nodded.

Notes, lines, and stanzas were etched in the rock — a complicated song. It brought back bad memories of Dan’s piano teacher, Mrs. Harsh, who’d quit giving him lessons last year after he painted her minor keys with Crazy Glue.

"What does it mean?" he asked.

"I don’t know," Amy said. "Franklin liked music — "

"Probably just decoration," Dan said impatiently. Something was rattling around inside the vase, and he was itching to open it. He put his hand on the lid.

"Dan, no!" Amy said.

But he opened it. Nothing bad happened. Dan reached inside and pulled out a corked glass cylinder wrapped in paper.

"What is that?" Amy asked.

"Liquid," Dan said. "A vial of something."

He untied the paper and tossed it aside.

"Hey!" Amy said. "That could be important."

"It’s just a wrapper."

She picked it up and unfolded it. She scanned whatever was on it and quickly tucked it in her shirt pocket. Dan didn’t care about that. He was trying to decipher the words etched on the glass vial. Inside was a thick green liquid, like the slime he used to play with and throw at his friends. The inscription read:

[proofreader’s note: printed on the vial is "Sa othu gearch sith, os I gearch ethe. Sue yht slslki het urtht ot efre."]

"What is that?"

Nellie said.

"German?" Amy asked.

"Uh-uh," Nellie said. "That’s no language I’ve ever seen."

Suddenly, Dan’s whole body tingled. The letters started rearranging themselves in his head. "It’s one of those word puzzles," he announced. "Where they scramble the letters."

"An anagram?" Amy said. "How can you tell?"

Dan couldn’t explain. It just made sense to him, the same way numbers did, or locks, or baseball card stats. "Give me a piece of paper and a pen."

Amy fished around in her bag. The only paper she could find was a piece of crème cardstock — their original clue about Poor Richard — but Dan didn’t care. He gave Amy the vial and took the paper. He turned it over and wrote on the back, unscrambling the anagram word by word:

As thou charge this, so I charge thee. Use thy skills the truth to free.

Nellie whistled. "Okay, I’m impressed."

"It’s the second clue," Dan said. "The second big one. This has to be it."

Amy frowned doubtfully. "Maybe. But what does it mean — As thou charge this?"

Suddenly, light flooded the room.

"Good job, cuz!" At the foot of the stairs, dripping wet but looking quite pleased with himself, was Jonah Wizard. His father stood behind him with a video camera.

"Man, this’ll make great TV." Jonah smiled wickedly. "This is the part where I swoop in, bust the lightweights, and gank the clue!"

CHAPTER 18

A rush of desperate energy filled Amy’s body, like it had when she’d pulled Dan out of the rail pit. She hadn’t come al this way to deal with a conceited jerk like Jonah Wizard. She imagined Grace’s voice in her head, speaking with total confidence: You will make me proud, Amy.

She raised the vial. "Back off, Jonah, or … or I’ll smash it!"

He laughed. "You wouldn’t." But he sounded nervous.

"Awesome footage!" Jonah’s dad said. "Keep it rolling, son. Great chemistry."

"And put down that camera!" Amy shouted.

Dan and Nellie stared at her in amazement, but Amy didn’t care. She didn’t care how valuable the vial might be, either. She’d had enough of the Cahill family’s backstabbing. She was so angry she did feel like throwing the glass cylinder against the floor.

Apparently, Jonah sensed it, too. "All right, cuz. Take it easy. We’re all friends here, right?"

"The camera!" Amy stepped forward like she was going to charge him.

Jonah flinched. "Dad, stop the camera."

"But, son-"

"Just do it!"

Reluctantly, Jonah’s dad stopped filming.

"Okay, Amy." Jonah put on his dazzling smile. "We’re good now, right? You know that’s the second clue. If you destroy it, the whole quest ends. Nobody gets anything.

That what you want?"

"Back up," she ordered, "into the corner. Go stand by Jane."

Jonah furrowed his eyebrows. "Who?"

"The mural. Go stand by the lady in the yellow — your great-great-great-great-great-grandmother."

Jonah clearly didn’t know what she was talking about, but he went along. He and his dad backed into the corner.

Dan whistled. "Nice job, sis."

"Get up the stairs," she told him. "You too, Nellie. Hurry!"

As soon as they were up, Amy fol owed, but she knew Jonah and his dad wouldn’t stay put for long.

"That was awesome!" Dan was bouncing up and down with excitement. "Can we seal them down there?"

"Dan, listen," she said. "The inscription

As thou charge this.

I think the stuff in this vial is inert."

"What’s a nert?"

"Inert! Like inactive. It needs energy to catalyze it. Franklin messed around with chemistry. When he says a ‘charge’ …"

Dan grinned. "Of course!"

"It’s dangerous."

"No choice."

"What are you guys talking — " Nellie glanced toward the street. "Oh, poop. Look!"

A purple ice cream truck was barreling toward them. It swerved to a stop in front of the gates. Eisenhower Holt scowled behind the wheel.

"Inside the church!" Amy said. "Quick!"

They raced up the path. Amy tugged open the sanctuary doors and crashed straight into a cherry-red suit.

"Hello, my dear children." Uncle Alistair smiled down at them. He looked like a raccoon with his two black eyes. Standing next to him was Irina Spasky.

Amy’s heart crawled into her throat. "You … you and her?"

"Now, now," the old man said. "I saved your life in the Catacombs. I told you alliances are important. I’m simply making friends where I can. I suggest you hand over that vial, my dear. I would hate for Cousin Irina to use her persuasive techniques."

Irina extended her fingernails. A tiny needle sprouted from each one.

Amy turned to run, but her eyes widened. Something was hurtling toward her from the street — a large white cube.

"Duck!" she yelled. Nellie, Dan, and she hit the floor as a crate of ice cream sailed over their heads. The crate must’ve been from the back of the freezer, because it crashed into Alistair and Irina like a block of cement and knocked them both flat.

"Revenge time!" Eisenhower Holt yelled, pulling more frozen ammunition from the back of his van. Arnold the pit bull barked excitedly. The whole Holt family charged up the sidewalk, each holding a crate of crème glacée.

"Amy," Dan said nervously. "Are you …"

He didn’t finish, but she knew what he was asking. The last time they’d encountered the Holts, Amy had panicked. This time she couldn’t afford to. That Cahill mural in the secret room had steeled her willpower.

"Nellie, get out of here," she ordered. "They don’t want you. Go call the police!"

"But-"

"That’s the best way you can help us. Go!" Amy didn’t wait for an answer. She and Dan dashed inside the church, leaping over the groaning forms of Alistair and Irina.