Prompt: A chase scene
"I'M GOING TO KILL YOU!" Ginny screamed as she hurtled down the stairs from her dormitory and threw herself into the common room, looking around frantically for her older brothers. There was a moment of complete and utter silence in the room before pretty much everyone in there started laughing their heads off. Ginny scowled around at all of them and, not seeing her brothers, flipped her suddenly purple hair over her shoulder and stormed over to Harry who was at least trying to keep a straight face.
"Give me the map," she demanded, holding her hand out and raising her eyebrow (which was also purple) as if she was challenging him to turn her down. He hesitated momentarily before pulling an old piece of parchment out of his inner pocket and passing it to her. She tapped it with her wand, muttering the words she'd heard the twins say to it so many times and scanned it quickly as the castle unfurled on it. A moment later she shoved it back into Harry's hand and took off in the direction of the kitchens where the two dots labelled Fred Weasley and George Weasley had been heading. Oh they were going to pay for tampering with her shampoo.
She saw them before they saw her but they definitely noticed the flash of light crack out of her wand and shoot towards them as she stalked down the corridor towards them.
"Sister dearest!" One of them cried jovially as they both ducked and started backing hurriedly away with giant smiles on their faces.
"Have you done something different with your hair?" The other added – she couldn't be bothered attempting to tell them apart as she flicked her wand and sent another jet of light cracking towards them again. Both twins yelped and took off, whooping with laughter as they ran. She sprinted after them, brilliant flashes of purple and blue light flying out of her wand as she attempted to hit them with the first hexes that came to mind. She'd get into trouble for this later but at the moment she didn't care. Her hair was purple, damn it, purple.
"Ginevra, we must say that purple is a great colour on you," the twins yelled over their shoulders as they skidded around a corner. She followed them, the incantation for the Bat Bogey Hex on her lips only for it to disappear as she turned into an empty corridor. She let out a scream of frustration and promised herself she'd find them and chase them again later and this time she would hit them with something. For now, however, she would go and find Hermione and ask her to fix her hair.