Amelia Bedelia hoisted the sail. Instantly, a gust of wind filled it with a reassuring pop. The sound reminded her of all the fun they’d had playing Pop the Question at the engagement party. That seemed like a million years ago. Amelia Bedelia felt as if she’d learned more today than she ever had in school. Way more than she even wanted to know, really. Being a grown-up sure didn’t seem like much fun to her.

Amelia Bedelia sat down beside Pearl, who was steering a course for Blackberry Island, the small island in the middle of the bay. Pearl, Jason, and Amelia Bedelia had named it after they’d discovered gobs of juicy blackberries growing there. That seemed like a billion years ago.

She told Pearl about shopping for a wedding dress, and how upset her aunt Mary had been when she’d seen Bob with a picnic basket and the other woman. Why was he going on a picnic with someone else when he was about to marry Aunt Mary?

“Yipes,” said Pearl. “Sounds stressful.” She handed a piece of rope to Amelia Bedelia. It was the same thickness as the line used for hoisting the sail, but only about six feet long.

“What’s this for?” asked Amelia Bedelia, holding it up.

“Well,” said Pearl, “if you’re going to get tied up in knots, you ought to know what you’re doing, right? Here’s a basic knot to tie a boat to a pier. A round turn with two half hitches.” She looped the line around a block of wood twice and made one half hitch, then another. Then it was Amelia Bedelia’s turn.

“Perfect,” said Pearl. “Now try it with one hand.”

“One-handed?” said Amelia Bedelia.

Pearl nodded. “In rough weather, one hand will be busy holding the boat steady while the other hand ties the two half hitches, securing the boat to the pier.”

Amelia Bedelia tied the knot using only her right hand. She did it again. And again. And again.

“Yippee!” yelled Amelia Bedelia on her fourth try.

“Great job,” said Pearl. “Once more, with your eyes shut.”

“What? Why?”

“At night, you might need one hand for steering and one hand for tying. You can’t grow a third hand to hold a flashlight. You’ve got to have a feel for it.”

Amelia Bedelia closed her eyes and got to work. Although she had her eyes shut, a movie was playing in her head. She imagined how the line should feel, twisting and turning, making first one, then two half hitches.

“Bravo,” said Pearl. “And that is just one knot. There are hundreds of different knots.”

“I thought there were just ten,” said Amelia Bedelia.

“Ten!” said Pearl. “What gave you that idea?”

“The signs all over the marina,” said Amelia Bedelia. “The ones that say ‘Limit Ten Knots.’”

Pearl laughed. “That type of knot measures speed. It means nautical miles per hour. A nautical mile on the water is a little longer than a mile on land.”

“So those signs saying ‘Limit Ten Knots’ . . .” Amelia Bedelia was still confused.

“That’s actually about eleven and a half miles per hour on land. Going faster makes a wave; we call it the wake. That causes tied-up boats to knock against the pier and get damaged.”

Pearl sailed closer to Blackberry Island. Amelia Bedelia could just see the roof of the deserted cottage in the middle of the island. But what got her attention was a brand-new dock extending into the water. A speedboat was tied to it.

“Perfect!” said Amelia Bedelia. “I’ll try a round turn with two half hitches.”

“Let’s anchor around the other side instead, and wade ashore,” said Pearl. “Those people in the boat could be pirates.” She laughed. “That’s the beauty of sailing—the boat is silent and you can be sneaky.”

They dropped the anchor, waded ashore, and began walking toward the cottage. When they got close, Amelia Bedelia and Pearl began crawling on their hands and knees, slinking silently through the bushes like a pair of stalking tigers. They considered themselves experts at sneaking up on people. Together they had snuck up on Jason and his pirate buddies, overhearing their plans to disrupt the annual Beach Ball.

“See?” said Amelia Bedelia. “The cottage looks just like it did when we left it, except the blackberries aren’t ripe yet this year. There’s no one here.”

Then a voice boomed behind them. “Hey, you kids! What are you doing on my island?”