A/N I don't own Harry Potter or anything else related to the books written by J.K. Rowling

Aunt Marge was coming over. Aunt Marge was coming over and Harry had to be nice to her. He remembered Uncle Vernon's words clearly; keep a civil tongue, no 'funny business', and he was now enrolled at St. Brutus's Secure Centre for Incurably Criminal Boys. Harry knew that if he disobeyed any one of these rules, Uncle Vernon would not sign his Hogesmeade permission form and beat the stuffing out of him. So that was why Harry sat in his room, waiting for the car to pull up into the driveway and his week to become hell.

"Harry!" He heard Aunt Petunia's shrill voice call from downstairs. No doubt she could see the car coming down the street but only by craning her long neck a certain way. Harry hurried down the stairs and found his cousin Dudley still watching TV but now wearing the new bow tie his mother had bought him.

"Fix your hair. Open the door for them." Aunt Petunia demanded. Not seeing a point to brushing his hair, it would stick up anyway, he opened the front door only to be nearly knocked to the floor as the very enormous Aunt Marge burst into the house, her brother following behind her carrying the luggage. He shoved the suitcases into Harry's arms and ordered him to take them upstairs.

"What will you have to drink Marge?" He added as he took off his coat. Harry sighed deeply and struggled to lift the bags up to the first landing. Scratch, scratch. Someone, or something was scratching at the door and Harry was hesitant to open it. Before he could act though, Uncle Vernon had reappeared and opened it himself. In came Ripper, Marge's favourite bulldog, and sadly to say, Harry's least favourite of Marge's large brood.

"Forgot the brute," He mumbled to himself. "What are you waiting for, get going!" He then yelled at Harry. Harry only nodded and again began to fight with the heavy suitcases. He rested for a moment at the top of the stairs before forcing himself back down. As he passed the front door, he heard a soft knocking. Again he hesitated to open it.

"Get the door boy!" He heard Uncle Vernon shout from the living room. So he did with clenched teeth. Outside stood a young girl, maybe 10 or 11 with long red hair and green eyes. She was wearing a purple zip up sweater, old jeans and in her hair she wore a worn yellow bandana. Slung across her shoulder was a bag unlike Harry had ever seen before, it was brown with tiny colorful stitching, beads hung from frayed ends, and it jingled every time she moved.

"Hello, I'm looking for my brother." She said her voice shy and timid.

"Sorry he's not here." Harry responded.

"I know he lives here: 4 Privet Dr. Is he in?" She asked again.

"No, no one here has a sister except for my uncle and his sister is already here. Bye." Harry tried to close the door but the girl stubbornly put her foot out.

"I'm looking for my brother and if you can't tell me where he is, I can and will do you harm!" The girl said through clenched teeth and although Harry didn't believe she could do him any real harm, he left the door open. "He has black hair and green eyes, like mine. He's 13 years old or will be, I'm not quite sure actually… but I know he lives here and his name is… his name is… Harry Potter." She said that last part really quietly then looked down at her feet, suddenly embarrassed.

"Listen, I don't know who you are but you're not Harry Potter's sister. Ok, you're not my sister!" Harry looked at her incredulously. Other witches and wizards had said some pretty strange things to him, about his life or theirs, but this beat them all.

After he made this statement, she looked up suddenly all smiles.

"Oh Harry!" She leapt at him trying to give him a hug but he pulled away.

"Who are you?" Suddenly Harry didn't like where this was going. The girl again looked embarrassed and a little scared.

"I'm Lucy. Lucy Petunia Potter and I am your sister Harry." She stared at him until he looked away, feeling awkward.

"How do I know you're telling me the truth?" He asked, then not willing to fall for it, added. "Obviously you're very confused and lost so can you just please go away?"

"I have proof." She paused. "But you're going to have to invite me in." Harry had to admit she was brave.

"Now's not a good time, could you come back tomorrow or something?" He looked over his shoulder at the lump on the couch that was Aunt Marge.

"Promise you'll be here?" She said. Harry nodded. "You have to say you'll promise!" She demanded. Harry rolled his eyes but promised anyway.

"Great, I'll see you tomorrow Harry." With that Lucy walked down the street then sat down on the curb at the corner. Harry shut the door and joined the group in the living room. A sister? Did he really have a sister? Time would only tell…