They ran toward the back of the sanctuary.

Amy didn't have time to admire the church, but she felt like she'd plunged into the Middle Ages. Gray stone columns soared up to a vaulted ceiling. Endless rows of wooden pews faced the altar, and stained glass windows glinted in the dim light of prayer candles. Their footsteps echoed on the stone tiles.

"There!" Dan yelled. A door stood open on their left -- a steep flight of stairs leading up. Amy latched the door behind them, but she knew it wouldn't hold the Holts for long.

They scrambled up the stairs. Dan started wheezing. Amy put her arm around him and half carried him.

Up, up, up. She hadn't realized the bell tower could be so high. Finally, she found a trapdoor and threw it open. Rain poured down on her face. They climbed into the belfry, which was open to the storm on all sides. A bronze bell the size of a file cabinet sat in one corner. It looked like it hadn't been rung in centuries.

"Help me!" Amy cried. She could hardly move the bell, but together, they managed to drag it on top of the trapdoor.

"That-should-hold," Dan wheezed. "Little-while."

Amy leaned out the side of the tower, into the rain and darkness. The graveyard looked impossibly far below. The cars on the street looked like the Matchbox toys Dan used to play with. Amy groped along the stone wall outside the window. Her fingers closed around a cold metal bar. A tiny set of rungs was embedded in the side of the tower, leading up to the steeple, about ten feet above her. If she fell...

"Stay here," she ordered Dan.

"No! Sis, you can't -- "

"I have to. Here, take this." She gave him the paper that had been wrapped around the vial. "Keep that dry and hidden."

Dan stuffed it into his pants. "Sis ..."

He looked terrified. Amy realized more than ever how alone they were in the world. All they had was each other.

She squeezed his shoulder. "I'll make it back, Dan. Don't worry."

BOOM!

The bell shuddered as someone underneath, someone very strong, slammed into the trapdoor.

BOOM!

Amy slipped the glass vial into her pocket and swung one leg out the window, into open darkness.

She could barely hang on. Rain stung her eyes. She didn't dare look down. She concentrated on the next rung of the ladder, and slowly, she pulled herself up onto the slanted tile roof.

Finally, she was at the peak. An old iron lightning rod pointed into the sky. At its base was a metal ring like a tiny basketball hoop, and below that a grounding wire, just like Franklin had recommended in his early experiments. Amy lashed the wire around her wrist, then took out the vial. It was so slippery she almost lost it. Carefully, she slipped it into the iron ring -- a perfect fit.

She inched back down the roof. "Please," she thought, holding on tight to the rungs.

She didn't have to wait long. The hair stood up on the back of her neck. She smelled something like burning aluminum foil, and then,

CRACCCCK!

The sky exploded. Sparks rained down all around her, hissing on the wet tiles. Dazed, she lost her balance and skittered down the roof. She grabbed frantically and caught a rung so hard pain shot up her wrist. But she held on and began to climb back to the top.

The glass vial was glowing. The green liquid inside was no longer murky and slimy. It seemed to be made of pure green light, trapped in glass. Carefully, Amy touched it.

There was no shock. It wasn't even warm. She slipped the vial out of its brace and put it back in her pocket.

As thou charge this, so I charge thee.

The hardest part was still to come. She had to get away safely and figure out what she'd just created.

"Dan! I did it!" She climbed back into the bell tower, but her smile melted. Dan was lying on the floor, bound and gagged. Standing over him, in black combat fatigues, was Ian Kabra.

"Hello, cousin." Ian held out a plastic syringe. "I'll trade you."

"MMMM!"

Dan struggled and tried to say something.

"MMMM! MMMM!"

"Let -- let him go!" Amy stammered. She was sure her face was bright red. She hated that she was stuttering again. Why did Ian Kabra turn her tongue to lead?

The bronze bell shuddered. The Holts were still pounding away below, trying to get through the trapdoor.

"You only have a few seconds before they come up," Ian warned. "Besides, your brother needs the antidote."

Amy's stomach clenched. "Wh-what have you done to him?"

"Nothing that can't be reversed if you act in the next minute or so." Ian dangled the antidote. "Give me Franklin's vial. It's a fair trade."

"MMM!"

Dan shook his head violently, but Amy couldn't risk losing him. Nothing was worth that. Not a clue. Not a treasure. Nothing.

She held out the glowing green vial. Ian took it and she snatched the antidote out of his hand. She knelt next to Dan and started tugging at the gag in his mouth.

Ian chuckled. "Nice doing business with you, cousin."

"You'll -- you'll never make it out of the tower. You're trapped up here the same as -- "

Then something occurred to her. How had Ian gotten up here in the first place? She noticed straps running across his chest, like a climbing harness. At his feet lay a bundle of metal poles and black silk.

"Another thing Franklin loved." Ian picked up his bundle and began fastening the black silk to the metal frame. "Kites. He pulled himself across the Charles River with one, did you know?"

"You couldn't have -- "

"Oh, yes I did." He pointed to the glowing dome of the larger church at the top of the hill. "I sailed right down from Sacré-Coeur. And now I'm going to sail right out again."

"You're a thief," Amy said.

Ian hooked his harness to the huge black kite. "Not a thief, Amy. A Lucian, the same as Benjamin Franklin. Whatever is in this vial, it belongs to the Lucians. I think old Ben would appreciate the irony of this!"

And just like that, Ian jumped out of the belfry. The wind took him. The kite must've been specially designed to support a human's weight, because Ian sailed smoothly down over the graveyard and fence and landed at a controlled run on the sidewalk.

Somewhere out in the storm, police sirens screamed. The bell shuddered as the Holt family pounded against the trapdoor.

"MMMM!"

"Dan!" Amy had completely forgotten him. She ripped off his gag.

"Ow!" he complained.

"Just hold still. I've got the antidote."

"Ian was bluffing!" Dan groaned. "I was trying to tell you. He didn't give me anything!

I'm not poisoned."

"Are you sure?"

"Positive! That stuff he gave you is useless. Or maybe it's poison."

Disgusted with herself for being so stupid, Amy threw down the syringe. She untied Dan and helped him stand.

The bronze bell shuddered once more and lurched aside. The trapdoor burst open.

Eisenhower Holt climbed into the belfry.

"You're too late," Dan told him. "Ian took it."

He pointed toward the street. A cab had just pulled up with Natalie Kabra in back. Ian climbed in and they took off through the streets of Montmartre.

Mr. Holt growled. "I'll make you both pay for this. I'll-"

Sirens wailed louder. The first police car appeared around the corner, blue lights flashing.

"Dad!" Reagan's voice called up from the stairs. "What's going on?"

A second police car appeared, racing toward the church.

"We're leaving," Eisenhower decided. He shouted down to his family: "Everybody, about face!" He took one last look at Amy and Dan.

"Next time..."

He let the threat hang in the air and left Amy and Dan alone in the tower.

Amy looked out into the rain. She spotted Uncle Alistair hobbling away down a side street, a Fudgesicle stuck to the back of his cherry-red suit. Irina Spasky 212

staggered out the front of the church, saw the police, and broke into a run.

"Arretez!" a policeman cried, and two of them started after her. Nellie was standing on the sidewalk with a few more officers. She was yelling frantically in French, pointing to the church.

Despite all the chaos, Amy felt strangely calm. Dan was alive. They'd survived the night. She'd done exactly what she needed to do. A smile crept over her face.

"Why are you so happy?" Dan complained. "We lost the second big clue. We've failed!"

"No," Amy said. "We haven't."

Dan stared at her. "Did that lightning fry your brain?"

"Dan, the vial wasn't the clue," she said. "That was just... well, I'm not sure what it was. A gift from Benjamin Franklin. Something to help in the search. But the real clue is that piece of paper you stuffed in your pants."

CHAPTER 19

Dan was thrilled that the second clue had been safely smuggled out of the church in his pants.

"So, really, I saved the day," he decided.

"Wait a minute," Amy said.

"I climbed onto the roof in the middle of a thunderstorm."

"Yeah, but the clue was in my pants."

Amy rolled her eyes. "You're right, Dan. You are the real hero."

Nellie cracked a smile. "You both did pretty good, if you ask me."

They were sitting together at a café on the Champs-élysées, watching the pedestrians and enjoying more pain au chocolat.

It was the morning after the storm. The sky was blue. They'd already packed their bags and checked out of the Maison des Gordons. All things considered, Dan felt lucky.

He still had some doubts about what they'd gone through. In particular, he didn't like that Ian and Natalie had gotten away. He'd hated being tied up, and he wanted to get back at Ian. But it could've been worse. At least they hadn't gotten lost forever in the Catacombs or slammed in the face with a box of ice cream.

"I still want to know what was in that vial, though," he said.

Amy twirled her hair thoughtfully. "Whatever it is, it's supposed to give one team an advantage freeing the truth -- that has to mean the final treasure of the contest. Since Ian and Natalie have the vial ... well, I've got a bad feeling we'll find out what it does pretty quick."

"If these Lucian dudes created it," Nellie said, chewing on her croissant, "maybe it's like some special kind of poison. They seem to love poisons."

"Maybe," Dan said, though the answer felt wrong. He still didn't like the idea that Ben Franklin was related to Ian and Natalie. He'd started to admire Franklin -- what with the fart essays and the lightning and all. Now he wasn't sure if old Ben was a good guy or a bad guy. "But what would poison have to do with a piece of sheet music?"

Amy took the parchment out of her backpack and spread it on the table. Dan had already studied it a dozen times. He knew it was an exact copy of the song they'd seen engraved on the stone pedestal in the secret room, but he didn't know why it was important. When he'd woken up that morning, Amy had already been researching on his laptop. Usually she didn't like the Internet. For some weird reason, she said books were better, so Dan knew she must've been really desperate for information.

"I found it online," Amy said.

"How?" Dan said.

"I did a search for Benjamin Franklin plus music. It came up right away. That's an adagio for armonica."