Addie's an Animagus

Dementors

On the morning of September first ministry cars arrived at the Leaky Cauldron. Addie got into the first car with the golden trio and Mister Weasley. While the remaining four got into the other car with Mrs Weasley. They got to the station with plenty of time to spare. Addie decided to sit with the twins and Lee. So told Hermione she'd share a carriage with her along with Harry and Ron when they reach Hogsmeade station.

Addie was sitting her compartment on the Hogwarts Express watching Fred and George play wizard chess. She and Lee made a bet out of who would win, the loser had to give the winner ten silver sickles. They were all dressed in their school robes as George won the game. Lee sighed as he handed a happy Addie 10 silver sickles. That she used to buy some chocolate from the trolley lady when she appeared.

As they were all laughing at something Fred had said about the trip to Egypt. The train suddenly stopped sending Addie forward into George. He caught as the lights went out and Brian hooted angrily at something outside. They heard someone say something about Dementors searching the train for Sirius Black. Addie was worried about her sister and friends.

Once they had left Addie shared some her chocolate with her friends. Remembering what her book on the Patronus charm said about how chocolate helps after a dementor attack. She then left to go check on her sister and other friends. As she saw an adult leaving a compartment and saw Hermione.

When she entered she hugged her sister before giving her some chocolate. Hermione told about how a dementor came into their compartment and tried to attack Harry. Then how Professor Lupin (adult that left the compartment) scared it away with a shield of light. A Patronus Addie thought as she walked back to her compartment after checking on Ginny, to tell the others that everyone was okay.

Ten minutes later they arrived at Hogsmeade station. As promised Addie went in a carriage with Harry, Hermione and Ron. Where Harry told her about how Sirius Black escaped Azkaban to come after him. Addie assured him that he'd be safe at Hogwarts and he cheered up.

(at Hogwarts)

Once they got to school they saw dementors guarding the gate to the school. Professor McGonagall pulled Harry and Hermione away from the crowd. They returned after the sorting where Professor Dumbledore explained how the dementors will be patrolling the perimeter of the school looking for Sirius Black. Until he was caught and that they would not enter the school grounds. Then they all went to their dorm rooms afterwards and fell asleep.