Finding Fred and George
The family walked through Diagon Alley, reminiscing about different events that had occurred there. When they passed Flourish and Blott's, Harry and Ron began extolling Mr. Weasley's brawl with Lucius Malfoy as one of the best things they'd ever seen. When they entered the ice cream shop, it was populated but not crowded. Molly and Arthur went to the counter where a smiling Fortescue greeted them. "Could I have…er…." Molly started. George's favorite? She knew this; it was something far too normal for his personality, she remembered. "Vanilla-Caramel Chunk in a waffle cone. With sprinkles," she added with a smile.
Fortescue nodded at her and looked at Arthur. "And you, sir?" he prompted.
"Strawberry-Peanut Butter with chocolate sprinkles and marshmallow fluff," Arthur recited.
"Right you are, right you are!" Fortescue said. He slid the purple envelope across the counter to them.
Taking it back to the group, Arthur opened it and read, "The picture on the other side of this clue is a picture of our greatest achievement. Go to it." Arthur flipped it over and the family glanced down at it. It showed a crowd in the Entrance Hall of Hogwarts, with two identical redheads hovering above them on broomsticks. One of the brooms had an iron peg hanging from it. The twins kept zooming out of the picture after saluting to Peeves, who was bobbing in the upper right hand corner.
"They're greatest achievement was leaving school?" Molly asked.
"But we can't go to the Entrance Hall," Hermione said. "Not with school in session."
"Well, they had to fly over the gates, I suppose," Tonks said. "Maybe we just have to get to the gates of the castle."
"Let's go try then," Harry said.
They began to walk back outside when Ron stopped short. "No," he said.
"No, what?" Arthur asked.
"We've got it wrong. Well, partly. It shows them leaving school, yeah, but that was to start up their store for good. Their greatest achievement was Weasley's Wizard Wheezes. We've got to go back to the shop."
From an alleyway nearby, Fred and George grinned brightly and Disapparated.
Ginny led the way back into the shop. They wandered around for a minute before spotting the storeroom door propped open. They entered and found the two people they'd been searching for all day.
"You've won!" the twins shouted. "Time to party!"
The family noticed the large W-shaped cake on the table. A corner had been cut out of it…
"Sorry," George said, not sounding it at all. "Couldn't help myself."
As they cut the cake and helped themselves to punch, Ginny asked, "So what was this all about? It was a great idea, how'd you think of it?"
The twins blushed, but the happy smiles did not vanish from their faces. "We were sort of…proving a point to ourselves," George said.
"We were feeling a bit neglected, I suppose," Fred continued. "So we wanted to test your twin knowledge, so to speak."
"Did you have fun?" George asked.
"Loads," Ron said through a mouthful of lemon cake.
"It was great," Arthur nodded, smiling.
"Brilliant!" Harry and Tonks said.
"Good, good," Fred nodded. "Mum? Ginny? Enjoy yourselves?"
Molly nodded vigorously, smiling at her sons. Ginny laughed and said, "Course I did. I would've gone home halfway through if I hadn't been having fun."
"Would you do it again next year?" George asked innocently.
"Uh-oh, why do I get the feeling this is about to become a tradition?" Tonks asked with a grin.
"There are worse ways to spend an April Fools' Day than finding Fred and George," Ginny said, and went back to refill her glass.