Jack ran after Annie. He caught up to her outside the huge building made of glass. She was standing in line waiting to buy tickets.

“Listen,” Jack said breathlessly, “we … we’ve got to make a plan. What if we suddenly find the sorcerer? What do we say to him? What if he tries to use his powers against us?”

“We use a rhyme,” said Annie.

“Which rhyme?” said Jack.

“How many, children?” interrupted the ticket seller. They’d reached the front of the line.

“Two, please,” said Annie, holding out some coins. The man gave her two tickets, and Annie turned back to Jack. “Let’s go inside and see if we can find the sorcerer. Then we can figure out which rhyme.”

“Okay, but be cool,” said Jack, “so the sorcerer doesn’t notice us.”

Jack and Annie walked through the entrance of the glass building. “Oh, man,” whispered Jack.

The Hall of Machines was the size of a football stadium. It was filled with thousands of people— and thousands of machines! Motors roared, wheels spun, gears clanked.

“What kind of place is this?” asked Annie.

Jack pulled out their guide book and read aloud:

In the Hall of Machines you will see machines from all over the world, bringing alive the world of engineers and inventors. You will see how cloth is sewn by machines to make clothes! You will see an exhibit of an automobile powered by gasoline! And of course, you will see a collection of inventions by the American grand-prize winner from Menlo Park, New Jersey—

“Look at that!” Annie interrupted. She pointed to a mechanical walkway overhead. The walkway circled the entire exhibit hall. Sightseers gazed down on all the exhibits. “We can get a look at everything from up there.”

“Good,” said Jack. “Maybe we can spot the sorcerer.”

He put away the guide book and led the way up the stairs. They stepped onto the crowded moving walkway and peered down at all the people milling about the exhibit hall below.

There were lots of men dressed in black coats and top hats. There were American cowboys and bearded men in Arab robes and headcloths. But Jack didn’t see a single scary-looking guy in a hooded cloak.

As Jack and Annie moved slowly over the exhibits, the air grew hotter and the sounds in the hall grew louder. Hammers hammered, sirens blew, bells rang, whistles whistled. The voices of other sightseers swirled around Jack and Annie. “What genius!” “The Age of Machines!” “He’s the Wizard of Menlo Park!”

“Did you hear that?” Annie shouted to Jack. “Someone said something about a wizard!”

“I heard!” said Jack. “The Wizard of Menlo Park! We just read something about Menlo Park.” He pulled out their guide book and found the page he’d been reading. He read aloud:

And of course, you will see a collection of inventions by the American grand-prize winner from Menlo Park, New Jersey—Mr. Thomas Alva Edison!

“Thomas Alva Edison!” said Jack. “He’s one of the most brilliant inventors who ever lived! Where’s his exhibit?” They looked down at all the booths. Directly below them was a booth with a big sign that said EDISON.

“There! Let’s go down!” said Annie.

When the moving walkway came to a staircase, Jack and Annie jumped off and hurried down to the main floor, squeezing past people as they went.

“Okay, where is it?” said Annie, looking around.

“Follow me,” said Jack. He led her down a wide aisle until they came to the Edison exhibit. Lots of people were gathered around the booth.

Jack and Annie slipped through the crowd to get a good look. Many of Thomas Edison’s inventions were on display. One of them had a big tube and lots of switches. Above it was a sign:

Phonograph

“What’s a phonograph?” Annie asked.

“I think it’s like an old-fashioned CD player,” said Jack. “It was the first thing that played recordings of music.”

A man with earphones was listening to the phonograph. Tears ran down his wrinkled face. “It’s incredible!” he said to the woman beside him. “Now we can hear the dead sing!”

“What does he mean?” Annie asked Jack.

“I guess he means that even after people die, you’ll still be able to hear their voices on the recordings,” said Jack.

“I never thought of it like that,” said Annie.

“Shh!” someone said. People were trying to listen to a man delivering a speech to the crowd. His name tag said: HENRI.

“Yes, indeed,” Henri was saying. “Thomas Alva Edison of Menlo Park, New Jersey, U.S.A., invented the phonograph, shown to the public for the first time here at the Paris World’s Fair. Mr. Edison has invented many other things, too.” Henri moved to another display in the booth: a lightbulb with a switch. He clicked the switch, turning the bulb on and off.

“Ten years ago, after years of work and thousands of experiments, Thomas Alva Edison invented the incandescent lightbulb,” said Henri. “When electricity passes through the thread, it gets very hot. There is no oxygen in the glass bulb, however. So the fire glows, but it does not burn.”

As others moved closer to the lightbulb to get a good look, Jack turned to Annie. “His fires glow, but they do not burn!” he whispered. “Thomas Edison is the Magician of Light!”

“I know!” said Annie. She turned to Henri. “Excuse me—is Mr. Edison in Menlo Park now?” she asked.

“No, as a matter of fact, Mr. Edison was here at this exhibit just a short while ago,” said Henri.

“Do you know where he is now?” asked Jack.

“No. All I know is that he was invited to a party and he left,” said Henri.

Jack felt the hair on his neck go up. “The sorcerer,” he whispered.

“Did a strange messenger in a cloak deliver the invitation?” asked Annie.

“Why, yes,” said Henri.

“Do you know where the messenger went after he left here?” Jack asked.

“He asked for directions to the Pasteur Institute. That is all I know,” said Henri.

“The Pasteur Institute?” said Jack. “Where’s that?”

But Henri didn’t answer. Another boy had asked him a question about the lightbulb.

“Come on,” Annie said to Jack. “We’ll find it somehow!”

As Jack and Annie left the Edison exhibit, they could hear Henri repeating his speech word for word: “Ten years ago, after years of work and thousands of experiments, Thomas Alva Edison invented the incandescent lightbulb….”