"Remember that time I got that Philosopher's stone back for Dumbledore?" asked Harry, quite out of the blue.
"Yes," said everyone, "but please do tell us again!"
"Very well," said Harry. "Gather round, fellow learners of the magic ways, and I'll tell you the story of Harry Potter... and the Philosopher's Stone!"
"Ooh," said someone.
"So anyway, this evil philosopher guy had a stone and he was using it to steal everyone's souls! Luckily, my owl heard everything and alerted me at once, using a language he and I worked out one night. Dumbledore wasn't standing for it, of course, and he sent me off at once. The philosopher lived on a volcanic island, and along the way I had many great adventures, the most noteworthy of which being -" (here he went off on a long list of unlikely-sounding adventures) "so anyway, I got the stone back and Dumbledore gave lots of points to Griffindor. It was pretty great."
"That's not really what happened, Harry," said Hermoine reproachfully.
"EXPERIAMUS!" screeched Harry, waving his wand and turning Hermoine into a frog. Ron quickly picked her up and ran off as the wonder boy unleashed his fury on the slower students.