Princess Petra Fixes It

Princess Petra lived in a tall, tall tower in the middle of a wide, wide meadow, and she was extremely bored.

"Any day now," said the royal messenger bird, who visited every Tuesday. "A brave knight will come and rescue you from the terrible dragon."

Petra looked out her window at the dragon, whose name was Humphrey. He was sitting in the meadow below, trying to toast a marshmallow on a stick. He kept accidentally melting the stick.

"Humphrey doesn't seem that terrible," Petra said.

"He's VERY terrible," said the messenger bird. "Now sit tight."

So Petra sat tight. She sat tight on Monday. She sat tight on Tuesday. She sat tight all the way through Wednesday and Thursday and the very long, very boring weekend.

No knight came.

She braided her hair. She unbraided her hair. She braided it again into eleven tiny braids and then unbraided those too. She counted the stones in the tower wall. There were four thousand, two hundred and seventeen. She counted them again just to be sure. Four thousand, two hundred and eighteen. She must have missed one.

"This," said Petra on the second Monday, "is ridiculous."

She looked around her tower room. There was a bed, a wardrobe, a stack of old books, and a trunk full of her grandmother's things. Petra opened the trunk and found six silk scarves, a pair of spectacles, a broken music box, and — right at the bottom — a big, dusty book called The Royal Guide to Engineering: How Things Work and How to Fix Them.

Petra blew the dust off the cover. She opened to the first page.

"Chapter One," she read aloud. "Simple Machines: The Lever."

She read Chapter One. Then she read Chapter Two: Pulleys. Then Chapter Three: Gears. Then she read Chapters Four, Five, Six, and Seven, which were about wheels, ramps, screws, and something wonderful called a compound machine, which was when you stuck a whole bunch of simple machines together to make them do something amazing.

By Tuesday, when the messenger bird arrived, Petra had read the entire book twice.

"Any news on the knight?" she asked.

"He's on his way! Probably! Could be weeks, though. Sit tight!"

Petra did not sit tight.

Instead, she took apart the broken music box. Inside she found tiny gears and springs and pins. She laid them all out on the floor and studied them. Then, using the diagrams in the book, she put the music box back together.

It played a little song. A tinkling, sweet melody that floated out the tower window and down, down, down to the meadow below.

Humphrey the dragon looked up. His big golden eyes went wide.

"What's that sound?" he called up.

"I fixed the music box!" Petra called down.

"You fixed it? How?"

"Gears!" said Petra. "The main gear was out of alignment. I just needed to reposition the drive pin."

There was a long pause.

"I know about gears," Humphrey said quietly. "I used to... well. Never mind."

But Petra was curious. "Used to what?"

Humphrey shuffled his enormous feet. "I used to build things. Before I got assigned to guard this tower. I built a water wheel once. And a little cart that rolled downhill all by itself."

Petra leaned so far out the window she nearly fell. "You're an engineer?"

"I'm a dragon," Humphrey said miserably. "Dragons don't get to be engineers. Dragons guard towers. That's what they told me."

Petra looked at Humphrey. Humphrey looked at Petra. And right then, Princess Petra had an idea so big it barely fit inside her head.

"Humphrey," she said. "How would you like to build something with me?"

"Build what?"

"A way down from this tower."

Humphrey blinked. "But — I'm supposed to be guarding you."

"You can guard me on the ground just as well as you can guard me up here."

Humphrey thought about this. He couldn't find a flaw in the logic.

"What do you need?" he asked.

Petra grinned. She opened The Royal Guide to Engineering to Chapter Twelve: Compound Pulley Systems.

"Wood!" she called down. "Long beams. Rope. And something heavy for a counterweight."

Humphrey lumbered into the forest at the edge of the meadow. He came back dragging four fallen trees. He used his claws — which were sharp as chisels — to strip the bark and square the edges. He was very precise. Better than any saw.

"Toss up the rope!" Petra called.

Humphrey tried to throw it, but dragon arms are short and stubby. So instead, he took a deep breath and blew the lightest, gentlest puff of warm air he could manage, and the coil of rope floated up, up, up to Petra's window.

"Nice!" said Petra.

She tied knots the way the book showed her, looping rope around a pulley she'd built from the music box gears, the wooden rod from the wardrobe, and a wheel she'd carved from the bedpost. She lowered one end to Humphrey.

"Now attach that to the counterweight platform," she called down.

Humphrey had built the platform himself — a wide, sturdy square of wood with a frame around it. He loaded it with heavy stones.

Petra built a second platform on her end, rigging it through the pulley system and out the window. When the counterweight dropped, her platform would lower gently to the ground. She tested the rope, checked the knots, and felt a flutter of excitement in her stomach.

"Wait," Humphrey called up. "The friction on that single pulley will make it jerky. You need a two-pulley compound system to smooth the descent."

Petra checked the book. He was absolutely right.

"Can you carve another wheel?" she asked.

Humphrey held up a claw and, with the delicacy of a jeweler, carved a perfect round wheel from a chunk of oak. He even made a groove around the middle for the rope to sit in.

Petra threaded the rope through both pulleys, tested the tension, checked every knot, tugged every beam, and then stood back to look at her machine.

It was beautiful. It was a proper, working, compound-pulley elevator system, hanging right off the side of the tower.

"Ready?" called Humphrey.

Petra took a deep breath. She stepped onto the platform. She held the guide rope in one hand and the release rope in the other.

She pulled.

The counterweight dropped. The platform shifted. And slowly, smoothly, perfectly, Princess Petra descended from the tower. The pulleys hummed. The rope slid through the grooves. Wind ruffled her eleven-times-braided-and-unbraided hair.

Her feet touched the grass.

She was on the ground.

Humphrey stared at her. Petra stared at Humphrey. He was much bigger up close. His scales were a shimmery green-gold, and his eyes were kind.

"We did it," Petra whispered.

"We did it," Humphrey whispered back.

And then they both burst out laughing — Petra's laugh bright and loud, and Humphrey's laugh like a rumbling, crackling bonfire.

That's when the knight finally showed up.

He came galloping across the meadow on a white horse, his armor clanking, his sword raised high. "FEAR NOT, PRINCESS!" he bellowed. "I SHALL SLAY THE DRAGON AND—"

He stopped. He looked at Petra, standing in the grass. He looked at Humphrey, standing next to her. He looked at the elevator system attached to the tower, with its pulleys and platforms and ropes and counterweights.

"What... what happened here?" the knight asked.

"I came down," said Petra.

"But — the dragon —"

"Humphrey helped me build the elevator. He's excellent with precision carving."

The knight looked at his sword. He looked at the elevator. He looked very confused.

"So... you don't need rescuing?"

"Nope," said Petra. "But if you want, you can help us with our next project."

"Next project?"

Petra pulled out The Royal Guide to Engineering and flipped to Chapter Twenty: Bridges.

"There's a village across the river that has no way to get to the market," she said. "Humphrey and I are going to build them a bridge."

The knight put away his sword. "I... don't know anything about bridges."

"That's okay," said Petra, handing him the book. "Start with Chapter One."

And so off they went — a princess, a dragon, and a knight — across the wide, wide meadow, toward the next thing that needed fixing.

And there was always a next thing that needed fixing.