A/N: Hey there! I know it's been over a month again, and I am so sorry! Also, if there are any mistakes in this chapter, please let me know, I'm really tired and I've been through this several times and am still finding things written in the wrong tense etc! Anyway, I just want to thank all those that have favourited or followed this story and also to Moon Lantern and Gruffard for reviewing, they are much appreciated! :)

As Ariella, Lottie and Archie entered the Room of Requirement that evening, the buzz of excitement was undeniable and it was clear that word had spread round of what Harry was going to teach them that lesson. The thought of being able to cast a patronus, such a highly looked on piece of magic was certainly something special, especially as it was never going to be taught to them in normal lessons.

"Hey!" a voice called to them as the three walked into the middle of the room, searching for a space to sit. "Over here!"

The friends looked over to where Huey, their Gryffindor classmate, was waving at them wildly, indicating to the spaces he had saved beside him. Hurrying over, Ariella, Lottie and Arcturus took their places just as the last few people came through the door.

"Right then, I think we're all here," Harry said as he stood up from where he'd been sat with Hermione and Ron. "So, as you all probably know by now, we're going to start having a go at producing a patronus today." He waited for the murmurings of excitement that rippled through the group to subside before continuing. "But remember that this is very advanced magic, you guys might not all master it in today's session, especially the first and second years in here."

There was a slight flurry of disappointment, but for Ariella, it only made her more determined. She wanted to prove them all wrong, and most of all, show her sister that she wasn't the only one to inherit brains and a talent for magic!

"Right, as we probably all know, the incantation for this spell is Expecto Patronum, and whilst there is no particular wand movement, the hardest part is keeping hold of that good memory whilst you cast the spell."

Everyone listened carefully as Harry continued to instruct them as well as he could before sending them off in twos and threes to different parts of the room. Obviously, Ariella stuck with Lottie and Archie, leading them over to a quiet corner so they could concentrate. She was determined on succeeding with this spell and today, if she possibly could. Looking up at the clock over the entranceway, she noted that they had about an hour and a half to two hours until this session finished. That was plenty of time.

"Okay, who wants to go first?" she asked her two friends. They had already decided previously that they were going to take it one at a time so the other two could comment on what they needed to do better to succeed.

"Can I go?" Lottie piped up, her voice betraying her excitement.

The other two stepped to one side as the auburn-haired girl closed her eyes tightly, a huge smile lighting up on her face as she brought her happiest memory into the front of her mind.

"Expecto Patronus!" she cried. Nothing happened. She looked questioningly at her friends, disappointment etching her features.

"It's Expecto Patronum, Lottie, you said it wrong, that's probably why it didn't work!" Archie told her, before urging her to have another go.

Half an hour later, and all she had managed was a wisp of white mist that lasted a mere two seconds before melting away. Lottie was saddened, but Harry, who had been standing nearby when she had conjured it, told her that for a first lesson, it was a very good attempt.

Next was Archie's turn, who in his half an hour managed to produce the faint outline of some kind of large fish. Ariella had thought it was a shark and Lottie was sure it looked more like a dolphin, but neither had been sure in the few seconds it had appeared.

Finally, it was Ariella's turn. Stepping away from her two fellow Gryffindors, she closed her eyes, searching her mind for a good memory she could use. Picking out the one of her under the sorting hat, she readied her wand before chanting the spell. She opened an eye. Nothing had happened. Closing her eyes again, she tried it once more.

"Expecto Patronum!"

Still nothing happened.

Quarter of an hour later and she had still managed to produce nothing.

"Perhaps try a different memory?" Archie suggested. "Maybe the one you have isn't strong enough. Harry said that sometimes that's the problem."

Ariella nodded, pursing her lips and trying to think of a happier memory. By now, there were all sorts of pearly white animals flying round the room. Annoyingly, she saw Hermione out of the corner of her eye, smiling as a small otter danced around her.

Holding onto the memory of getting her Hogwarts letter, she tried again, determined to get up to standard with her older sister.

"Expecto Patronum!"

Gasps from her two friends had her eyes flying open. The remnants of a white mist were dissolving into the air in front of her.

"That looked good, Ella! Have another go for me?" Harry's voice said from the other side of her.

Ariella did as she was told and once more the mist appeared for a few seconds and disappeared again. She turned to look at Harry, hoping he would have something to say that would help her to improve.

"You're doing everything right which suggests that the memory you have isn't strong enough. Is there another memory that is stronger than this one?"

The young girl wracked her brain, thinking of another moment better than finding out that she was a witch. She had had a happy childhood, but none of that equalled the memory that she had just used.

"What about casting your first spell?" Lottie suggested.

Ariella thought back to getting the Wingardium Leviosa spell right. As much as she had loved that moment, it still didn't rival receiving her Hogwarts letter. Then she realised that it wasn't all about lessons and success in that way, but also success in other ways. And what was the moment she was most proud of? Joining the DA, of course. She got to spend time with her friends and her sister, she could practise more spells than in class and it was all against the wishes of that toad, Professor Umbridge! What could possibly be better?

Closing her eyes tightly, she brought back the excitement she felt when first entering the Room of Requirement all those months ago. She focused on the laughter of her friends when the force of her own spell knocked her backwards so that she landed hard on the floor, the proudness when she finally managed to stun Archie, the smug facial expression she could give her sister when she managed to do that spell a few minutes before Hermione.

"Expecto Patronum!" she cried once more, a huge grin on her face.

She only cracked open an eye when she heard Harry gasp and then she nearly stumbled backwards in shock. A large, pearly phoenix was hovering in front of her, its powerful wings beating in the air before it took off round the room.

"Ella?" Hermione's voice called out in amazement as the young girl sent her patronus over to where her sister was still playing with her otter. "Is this yours?"

When Ariella nodded, the older girl ran over and embraced her, overjoyed that her younger sister had managed such a complicated spell so soon.

"Well done! It's magnificent!" she whispered as the two watched the phoenix as it soared in and out of the eaves above.

However, the jubilation didn't last long as a loud bang suddenly sounded out from one of the walls, making the entire room shake.

The moment Ariella lost her concentration, her patronus disappeared. So did everyone else's as the students stared at the wall fearfully. Another bang sounded and the room went completely silent. No one moved a muscle.

At the next bang, one of the mirrors cracked and shattered and it became horrifyingly clear that they had been found out. Hesitantly, one of the second-years walked forward, only to jump back as another bang made a small hole appear in the crack on the wall.

Suddenly the room erupted into chaos as Harry screamed at them to run. Grabbing Lottie and Archie's hands, the three ran for the door, following behind everyone else. If they were caught, they would be in serious trouble.

However, as soon as they were out in the corridor, red flashes of the stupefy spell flew in all directions as members from the Inquisitorial squad came at them, forcing everyone to split up and run down any corridor they could find. In all the confusion, Ariella's hand was pulled from her friends' grip and she was forced to sprint away from the group, hopping onto a staircase just as it started pulling away from the corridor.

Separating from the rest of the students, Ariella ran off, hoping than any Squad members would run after the big groups rather than her. She darted down several small hallways, hoping to throw off anyone who was following her. As she ran out of breath, she stopped half way down a silent and empty passageway, leaning against one of the cool stone walls as she got her breath back.

It was getting dark, she realised, as she looked out of the window at the end of the hall, which meant that she needed to somehow find a way back to the Gryffindor common room without being seen by anyone in the Inquisitorial Squad.

She was just about to stand up to get moving again when suddenly footsteps rounded the corner in front of her. Standing up, Ariella went to run, especially as when the person spotted her, they sped up. Realising that it could only be a member of the Inquisitorial Squad, she cast a quick stupefy behind her and ran for it. It seemed her spell had missed them for the footsteps continued until there was a loud shout.

"Incarcerous!"

Thick ropes wrapped themselves around the young girl's ankles, causing her to squeal as she crashed to the floor. Immediately, she tried to crawl forwards on her hands and knees, but she didn't get very far before a hand snaked around her arm and hauled her to her feet.

"Got you now, Mudblood," hissed a terrifyingly familiar voice.