The Maze of Bones (The 39 Clues #1)(22)

"Oh!" the librarian said. "Very ingenious. We have one of those for our collection."

Amy looked up. "Why? What do they do?"

"They reveal secret writing," the librarian said. "During the Revolutionary War, spies would use invisible ink to send messages on documents that seemed harmless, like love letters or orders for merchants. The receiver would use heat or a special chemical wash to make secret words appear between the lines. Of course we can't damage our documents by spraying chemicals on them, so we use black light to check for secret messages instead." Amy held up the black light reader. "Can we -- "

"I can save you time, my dear," the librarian said.

"We check all our colonial documents as a matter of course. There are no secret messages, unfortunately."

Amy's heart sank. They'd wasted their time here, and she still didn't know what she was looking for. She had a mental list of other places to visit, but it was very long.

There was no way they could hit them all before eight tonight.

Secret messages.

Franklin had written lots of letters to his friends and family while living in Europe.

Follow Franklin. A crazy idea started to form in her head.

Amy looked at the librarian. "You said his letters were important to him. Is there anyplace else that keeps Franklin's letters on display?"

The librarian smiled. "Funny you should ask. Some of his most famous handwritten documents are showing this month at the Franklin Institute down on -- "

"The science museum?" Amy shot to her feet. "On 20th Street?"

"Yes." The librarian looked startled. "But how did you -- "

"Thanks!" Amy rushed out of the room with Dan right behind her.

It was a quick drive to the Franklin Institute. Nellie wasn't too thrilled to sit in the car with the cat again, but Dan and Amy convinced her they wouldn't be long. They ran inside and found a twenty-foot-tall white marble statue of Benjamin Franklin gazing down at them from a giant chair in the entry chamber.

"Holy almanacs," Dan said. "That's a big Ben."

Amy nodded. "At the end of his life, he was so heavy he had to be hauled around in a sedan chair carried by four big convicts."

"Sweet," Dan said. "I want a sedan chair."

"You weigh ninety pounds."

"RESOLUTION: Start eating more ice cream."

"Just come on!"

The museum was huge. They walked past the memorial and through the ticket area, then followed the map into the Franklin Gallery. It was already late in the afternoon and the place was pretty much deserted.

"Check this out!" Dan picked up a mechanical arm and grabbed Amy's wrist with it.

"Stop that!" she said. "Franklin made that for getting things off high shelves, not annoying your sister."

"I bet if he had a sister -- "

"He did have a sister! Dan, we need to find his letters. Stop messing around."

They kept walking .They found a display of Franklin's lightning rods, a bunch of bifocals, and one of his batteries for generating electricity -- a wooden crate full of glass jars, all wired together.

"That thing is huge," Dan said. "What is that, like, a double Z battery? And whoa, what is that?"

He ran over to another display. Inside was a mahogany box holding a row of closely fitted glass saucers, like a stack of cereal bowls.

"It's an armonica," Amy said, reading the description. "It makes music by rubbing water on the rims of the glasses."

"Awesome. Franklin invented that?"

"Yeah. Says here it was really popular for a while. Lots of famous composers wrote music for ..."

Amy froze. A tall gray-haired man had just crossed the hallway in the next gallery, heading toward the information desk. And he was wearing a black suit.

"What?" Dan asked.

"Man in black," Amy murmured. "Run!"

She grabbed her brother's hand and they fled deeper into the gallery. They didn't stop until they were two rooms away, hiding behind a large glass sphere that showed the solar system.

"What's he doing here?" Amy fretted.

"Duh," Dan said. "The fire didn't work, so he's here to get us! We can't go out the main exit. He'll be waiting to jump us as soon as we try."

Amy looked around nervously for another way out. Then she noticed what was on the wall right next to them. Documents. Cases full of documents -- all yellowing parchment, written in spidery handwriting.

"Franklin's letters!" she said. "Quick, the black light reader!"

Dan fumbled in his backpack and brought out the light. They held it up to the first letter and shone it through the glass. The document seemed to be some kind of request for supplies. It started:

Sir, I wrote to you lately via New York, which I hope may come to hand. I have only time now to desire you to send me the following items, viz.

1 Doz. Cole's

Eng. Dictionaries

3 Doz. Mathers Young Man's Compan'n

1 Qty. Iron Solute

2 Quarter Waggoners for

America

Purple light passed over the paper, but nothing happened.

"Next!" Amy said. She was sure the man in black was going to burst in on them any second.