Title: Snape's Demigod Daughter

Rating: T

Summary: Cassandra Snape comes to Hogwarts during Harry's third year. She's different from other students right from the start. And she has a very nasty view of the word 'Muggle.' To make things even stranger, for Harry, she's Petunia Dursley's sister and brings her sister along for the ride. A crossover of Harry Potter and Percy Jackson.

Disclaimer: I don't own any of Rowling or Riordan's characters and I'm making nothing from this.

Chapter 2

"Why are you hiding?" Cassandra asked her sister.

"I don't want any of those blasted Weasley's to see me," she said, "I want my entrance to be a surprise. Anyway, I have to make sure that these grounds are safe enough. I'm not having a monster attacking you, or anyone else."

"Thanks," Cassandra said and then she left to join the other students.

When they reached the boats Cassandra backed away in horror. Her mother might control the earth, sky, and sea but the idea of going across a lake didn't appeal to her.

"What's wrong, afraid of water?" one boy taunted.

"How about I throw you in," Cassandra threatened.

The look that she gave him indicated that she would make very good on her threat. He jumped into a boat and a couple of moments later, having no choice in the matter, she climbed in. The whole trip she closed her eyes, praying over and over again for protection. When she sensed land she opened her eyes and jumped out so fast that she knocked a girl over.

"Hay watch it," she hissed at her, but Cassandra didn't stop to say that she was sorry.

She didn't see her sister at all, including right before the Sorting. She figured that she was still checking out the defenses of the school. The sorting was the dumbest thing that she had ever heard of in her life. All it did was create a problem between those whose families had been magical for centuries and those that were just beginning. Of course, to her, they were all bigots that really needed to be given some training in common sense.

"Snape, Cassandra," a tiny man called out.

Everyone stared at her and she glared at them, major. She took the hat and, instead of facing the students, she turned her back on them. She looked down at it and said, "If you look into my head I will recreate the Salem Witchcraft Trials with you being burned. I don't allow a talking fashion flop from the dark ages decide which house I'm going to be in. I make my own choices! You have no say in that part of my life. So I dare you to try it, kindling."

"G-G-GRYFFINDOR!" it screamed, "Get her away from me."

"Glad we have come to a wonderful agreement," Cassandra said and she threw the hat on the ground.

Everyone gasped in shock and then the doors were thrown open, making everyone turn.

"THAT'S MY WONDERFUL SISTER!" Petunia screamed at the top of her lungs.

And then, chiton flowing around her Petunia made her way down the middle of the hall.

Everyone shuttered as she passed, the magic coming off of her was beyond anything that their essence had sensed. Cassandra knew that she was doing on purpose, to show them who was really in-charged. She glared at them all and Cassandra knew that she was angry at those that had polluted her sister's mind, made her believe that Lily Evens magic was so much greater than that of the daughter of Hecate. Even if she had never told.

"Your ghouls were giving me a headache," she told them, "So, I got rid of them."

"Mrs. Dursley, how?"

"And this comes from the man that polluted my sister's mind," she snarled, "Made her think that she was better than her oldest sister. Did you not think that I had magic, or where you thinking there was only one kind?"

"Your name wasn't on the roll," he said.

"Yet, here I am," she said. "Able to see your world and all its so-called wonders. I have seen greater wonders than even you can produce and I have far greater magic than you do. All of you are second rate magical people with your Tom Riddle being the worst of them. You call those below you muggles when they have done far greater things than you can imagine.

"They have built great cities, empires, but all you have done is created something that you think belongs to you. You created a world out of the rubble of nothing, though it turns out to be the same. My blood comes from the past, blood that you shall never share. You're only given the gift, I am the gift. Keep your wonders; I have no need of them. But by time all is said and done, you will understand exactly what I'm talking about."

She then changed into a falcon and flew away. Cassandra grinned at their shocked faces and then headed for the Gryffindor table. That should keep them on their toes for a couple of months.

To say that the feast was memorable would be an understatement. Everyone was staring at her as though she was some strange witch from Greece, or something. Cassandra didn't let them bother her. She had a rat to find and she wasn't going to rest until she found it. She could sense things that no other person could, and that would make all the difference.

She gave her offering to her mother and then began to eat. That alone got her even more looks. Finally she just got tired of it and turned on them, her eyes flashing red with anger. The boy that was next to her screamed in horror and ran out of the Great Hall. Good, she didn't have to put up with him. When the feast was finally over, and she got up, she was given the widest breath that anyone had ever given her.

She figured that most had gotten the impression that she wasn't like everyone else.

When she finally arrived inside Gryffindor Tower she found her trunk, and everything else, waiting on her. The falcon, which she knew to be her sister, was on her bed. At once it changed back to her sister.

"You made quiet the impression," Cassandra told her.

"That was the whole point," she said, "Anyway, I was telling the truth when I said that I'm not impressed with this place. This place turned my sister into something that I didn't recognize. She boasted about how much better her magic was and made me feel as though I was nothing. Well, anyway, I was checking out the grounds after I got rid of those ghouls. Their piss poor in my opinion so I was thinking about us working on them so that their like the boarders of camp."

"Sounds like a good idea," she said.

"Glad you agree," Petunia said, "Well I'm heading to bed. I want to be fresh to give that dumb Headmaster a hard time."

She changed back into a falcon and vanished through the window.

Cassandra magically changed her clothes into her nightgown just as the rest of the girl's came in. They were both armed with wands, but Cassandra didn't pay them any attention. They were morons that thought magic solved all their problems.

"S-S-Stay away from us, Snape," one of them said, shaking with fear.

"Oh I intend to do just that," she said and then she closed the curtains.

It didn't take long for her to finally go to sleep.

The next morning all the beds were occupied with her moronic roommates. She went to take a shower and then got into her uniform. Grabbing several scrolls, she couldn't even understand the need for books, she grabbed what she had and magically disappeared. She appeared outside the Great Hall, making the Caretaker jump. He glared at her, but she had already gone inside. Though she could sense that he had glared at her. The Great Hall was not even full of people, but she did see a girl from the Ravenclaw table that looked familiar.

"Luna," she called out.

She looked up from her magazine and at once Cassandra knew that this was Luna, daughter of Athena. She stared at her and then said, "Cass, there you are."

"I'm always here," she said.

"When did you get here?" Luna asked, "I was stuck in the wing due to the ghouls."

"Last night, with the others," she said.

"I heard everyone in Ravenclaw talk about you," she said, "I couldn't believe that Hecate allowed you to come, knowing how much you hate her pet world."

"I only hate it because of the bigots," Cassandra clarified.

"Yeah, I get that," Luna said. "You're going to have some problems. Hermione Granger is at the top of her class and she's going to look at you as someone that might unseat her."

"Oh that would be so horrible," Cassandra mocked, which made Luna laugh.

"Oh your dad's coming," Luna announced, "Along with that Lupin fellow."

Cassandra sniffed the air and got a smell of wolf. The man was a damn werewolf. Well, now this was interesting. This also gave her an idea.

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A/N: Now what grand idea does Cassandra have? Well you'll find out soon enough.