Melody and Hazel, the twin Potter sisters, stuffed their backpacks under their seats. A girl's face peeked in the door. "Can I sit with you?" Melody grinned. "Sure." The girl tossed a backpack next to her and brought in a covered basket. "Here you go, Tammy." She lifted the cover, and a marmalade-colored cat jumped out. "What's your name?" the girl asked. "Melody," said Melody. "And this is Hazel." The girl looked confused. "Wait . . . who's Hazel and who's Melody?" the twins laughed. "We're twins," Hazel explained. "We look a lot alike, but my hair is darker than hers. I'm Hazel." The girl smiled. "I'm Elena Lupin. You look familiar . . . what's your last name?" "Potter," the twins said in unison. "Well, that explains it. There's the trolley!" Melody leapt up. She pulled a sack from her pocket. "Two - no, three licorice wands, six pumpkin pasties, seven Droobles', twenty chocolate frogs, and eighteen packs of Bertie Bott's Every Flavor Beans." Elena stared. "You're not going to eat anything at Hogwarts at that rate!" "Oh, relax." Melody plopped back down. "Licorice wand, Elena?" Elena looked doubtful. "Okay . . . but I've heard that the feasts are AWESOME at Hogwarts." "Yeah, Mel," Hazel chimed in. "Easy on the sweets." Melody looked at her sister