By Superpower37

Disclaimers: I only own Katie.

Author's note: Yeah, I know Lucas only had an older sister, Autumn, but I thought it would be fun if he had a younger one.

Chapter 1: You Look Familiar

Lucas Grabeel and the other High School Musical cast members were gathered in a room. They had been told that a new member was joining the cast. A girl who looked to be two years younger than him walked in. She had long, straight blond hair and sky blue eyes. To Lucas, there was something oddly familiar about her.

"Everyone! This is Katie, she's the new member of our cast. Please be nice to her" Kenny Ortega, the director announced. They all filed out. Lucas went to talk to her, but Zac Efron began talking to her. He didn't see her again until after the shoot was done.

"Katie! Katie wait up" he called. Katie turned around and waited for him.

"Hey. You play Ryan Evans right" she asked. He smiled and nodded.

"My name's Lucas Grabeel" he said extending his hand. She gladly took it and they shook each other's hands.

"Katie. Just Katie" she said. Lucas cocked an eyebrow.

"What's your last name" he asked.

"I don't have one" she replied calmly.

"Everyone has a last name" Lucas pointed out. Katie sighed and looked away.

"I don't. I live in a foster center with all kids waiting to be adopted. I've lived there for most of my life" she told him. Lucas felt bad, his life was almost perfect. He had a loving mom, and a great dad. Katie didn't have that, at least he thought that.

"Have you ever met your parents" he asked.

"No, I was left at the hospital after I was born" she replied (AN: Her mother didn't literally get up and walk out, she had to rest for a couple of days).

"What year where you born" Lucas asked.

"1986" Katie said laughing "What? How old did you think I was? 40".

"No, you don't look that old. 21 maybe" Lucas laughed.

"Almost, 20" Katie giggled.

"Yeah, and it's the year 2007" Lucas teased. They said goodbye when they reached Katie's hotel room door. After the door closed, Lucas sped up his walking. What Katie said had gotten him thinking. There was one memory of his mom looking huge and that was when he was two. He would never forget that memory. He picked up the phone and dialed.

"Hello" his mom's voice asked.

"Mom, I need you to tell me something straight forward" he asked sternly.

"Alright honey" she said hesitantly.

"Do I have a younger sister" he asked.

"Yes, she's two years younger than you" his mom said. Lucas gasped, his sister was Katie.

"Why did you abandon her mom" he asked yelling "I found her. She's been living in a foster center with no idea who her parents are and nobody to really protect her". His mom began to cry.

"I don't know. I-I just felt it was right" she sobbed.

"Right to just abandon her, not to tell her only brother? That's not right" Lucas bellowed before slamming the phone onto its cradle. He sat down on the bed and put his head in his hands. How was he supposed to tell her? He walked down the hall to her room and knocked.

"Lucas? What's wrong" Katie asked.

"Can I speak to you" he asked. She let him into her room. He looked at her. Now that he thought about it, she looked a lot like him. She had his blue eyes, his blond hair, his face, his smile. She was built like their mother while he was built like their father.

"What's wrong Lucas" Katie asked. He took a deep breath.

"I just found out that you're my sister" he said nervously. She stared at him.

What happens next? Please R&R!