Andrew bought a mysterious prank potion in Hogsmeade. The shopkeeper called it an accidental concoction, saying its effects were unknown, but that it would likely wear off within three days. Unable to resist his curiosity, Andrew drank it—and now he's a ghost!

The bottle rolled across the carpet in his dormitory, and when he looked at himself, he realized he was completely transparent, unlike any other Hogwarts ghost, and no one seemed to be able to hear him!

"Wow, this is really cool, but it also feels a bit strange..."

He tried to pick up the bottle to read the label, but his fingers just went straight through it.

"What the heck..."

Yes, he had now become nothing more than a sentient cloud of air. After a brief moment of panic, Andrew reassured himself that the potion's effects would last no more than three days, but he also remembered that it was just an experimental concoction by the potion seller. He began to feel uneasy and inwardly vowed never to buy any more untested potions again. While he sighed helplessly, he also discovered some unexpected pleasures. Now, as a mere puff of air, he could fly through the air, pass through any wall, and secretly observe and eavesdrop on everything! Just as he was daydreaming about how to make the most of his current situation and have some fun, the dormitory door opened. His roommate, who was also his arch-rival, walked in……