When Hermione asked for Addie's help to make a Polyjuice potion. She disagreed at first before she heard Malfoy was involved and she agreed. They came up with the idea to do it the abandoned girls bathroom on the second floor. It was abandoned due to the ghost that lived there and the toilets were always out of order.

The first thing they have to do is get the book with the recipe in it. But it was in the restricted section of the library. They needed a teachers permission to borrow it. So they choose Lockhart and Hermione told him she wanted a book for his lesson. He didn't even look at the name of the book she wanted as he talked about himself, signing the permission slip.

Hermione didn't want to give up the permission slip until Addie glared at her. madame Pince soon returned with the book they wanted. They all went to a quiet corner where Addie and Hermione read over the recipe. They told the boys it'd take a month to make, Harry and Ron complained saying that half the muggle borns would be in the hospital wing or worse dead in a month. But Hermione calmed them down and told them it was the only plan they had.

After potions Addie distracted Professor Snape as Hermione got the ingredients needed for the potion from his private stock. Addie asked Snape about dragons blood and its use in potion making. When Hermione came out of the room, Addie said goodbye to the Professor Snape.

As Addie and Hermione started brewing the potion in a spare cauldron. Harry and Ron entered the bathroom asking why they were doing this in girls bathroom during the day. Hermione told them about Moaning Martel who came out of her cubicle. Addie continued to brew the potion by stirring it adding a few ingredients why reading the instructions.

They put it a cubicle before they went to dinner. Then Addie went back to the library still trying to find out want was doing this. After half an hour of searching she had no luck and went to her secret room to practice her two spells. When she final got back to Gryffindor tower at 11 o'clock in the evening. Everyone else was asleep as she tip-toed to her bed, where Brian was sleeping peacefully on her headboard.

(1 month later)

Addie had decided not to take the Polyjuice Potion, she told them she had a lot of homework to do. It wasn't a lie, but it also wasn't entirely true. She wanted to practice her two spells again as she hasn't been able to lately. Because she had been helping Hermione make the potion. She also almost learnt to do the Patronus charm properly and wanted to prefect it.

When she managed to do it after an hour practicing it she was thrilled. It was a Marten, her happy thought was of the time she played Quidditch with the Weasley twins or helped them with a new prank. She then practiced turning into her animal form and she almost had it. But it was time for her to return to the common room.

On her way back to Gryffindor tower Professor McGonagall appeared. "Follow me Miss Granger" is all she said before walking back the way she came. Addie followed her and tried to ask her where they were going. When they got to the hospital wing however and so her older twin sister with a cat face, ears and tail. She lost it and ended rolling around on the floor laughing her heat out. "This is not a laughing matter Miss Granger" McGonagall told the girl on the floor sternly.

When she had calmed down Addie asked Hermione want had happened. Hermione told her it was hair she had plucked from someone (Slytherin) elses robes. But it turned out to be cat fur, not human hair. Madam Pomfrey told them Hermione had to stay until she stopped coughing up fur balls. As Hermione took a potion that turned her back to normal and coughed up a fur ball. Addie was about to laugh again, but Professor McGonagall gave her a stern look.

When she got back to the common room she told Harry and Ron that her sister would be fine. They told her what they found out from Malfoy, apparently the chamber of secrets has been opened before. Fifty years ago.

Once they left she told the Weasley twins an d they all ended up on the floor laughing together. George asked her how her training was going and she told them she'd mastered the patronus charm. She looked around the room to see no one else around and showed them her patronus. They smiled congratulating her before returning to their separate dorms to go to sleep.

A/N

Picture of Addie's corporeal Patronus above