The DA had finally started work on Patronuses, which everybody had been very keen to practice, though - as Harry kept reminding them - producing a Patronus in the middle of a brightly lit classroom when they were not under threat was very different from producing it when confronted by something like a Dementor.
"Oh, don't be such a kill joy," said Cho brightly, watching her silvery swan-shaped Patronus soar around the Room of Requirement during their last lesson before Easter. "They're so pretty!"
"They're not supposed to be pretty, they're supposed to protect you," said Harry, patiently. "What we really need is a Boggart or something; that's how I learned, I had to conjure a Patronus while the Boggart was pretending to be a Dementor -"
"But that would be really scary!" said Lavender Brown, who was shooting puffs of silver vapor out of the end of her wand. "And I still - can't - do it!" she added angrily.
Harry soothed her and went to help Neville. Isabella watched as her lion yawned and flopped on the floor.
"You would have an animal that sleeps," Alex laughed. She had only succeeded in forming a shield Patronus, and Morgan's face was screwed up in concentration as her wand produced mere wisps of silver mist. Luna watched her silvery hare hop about the room wildly.
The door of the Room of Requirement opened, and closed. Isabella fell silent as a tiny house-elf with large, ping-pong sized eyes squeezed past her. Villa Petrroci had a staff of five house-elves, but this one was very strange. He had about eight knit hats balanced between his large bat-like ears. His feet were equally swollen by the number of socks he wore.
The house-elf went up to Harry and tugged his sleeve. Harry looked down in astonishment and seemed to recognize the elf.
"Dobby!" he said. "What are you - What's wrong?"
The elf's eyes were wide with terror and he was shaking. Everybody stopped what they were doing to watch Dobby. Isabella's lion melted into the carpet at her feet, along with everyone else's Patronuses, leaving the room much darker than before.
"Harry Potter, sir..." squeaked the elf, trembling from head to foot. "Harry Potter, sir... Dobby has come to warn you... but the house-elves have been warned not to tell..." Suddenly the elf ran headfirst at the wall. Harry made to seize him, but Dobby merely bounced off the stone, cushioned by his eight hats. Isabella and a few other girls let of squeaks of fear and sympathy. The Petrroci elves never punished themselves, because they were ordered not to.
"What's happened, Dobby?" Harry asked, grabbing he elf's tiny arm.
"Harry Potter... she... she..." Dobby hit himself hard on the nose with his free fist. Harry seized that, too.
"Who's 'she', Dobby?" But Isabella thought she knew; surely only one 'she' could induce such fear? The elf looked up at Harry, slightly cross-eyed and mouthed wordlessly.
"Umbridge?" asked Harry, horrified. Dobby nodded, then tried to bang his head on Harry's knees. Harry held him at arm's length.
"What about her? Dobby - she hasn't found out about this - about us - about the DA?" He seemed to read the answer in the elf's stricken face. Dobby's little hands were held fast by Harry, so the elf tried to kick himself and fell to the floor.
"Is she coming?" Harry asked quietly. Dobby let out a howl, and began beating his stockinged feet on the floor.
"Yes, Harry Potter, yes!" Harry straightened up and looked around at the motionless, terrified people gazing at the thrashing elf.
"WHAT ARE YOU WAITING FOR?" Harry bellowed. "RUN!"
They all pelted toward the exit at once, forming a scrum at the door, then people burst through. Isabella was separated from Alex, Luna, and Morgan by the crowd. She saw Terry sprinting down the hallway, but then she was swept the other way. Hands grabbed her on either side; Fred and George were pulling her the other way.
"Come on, the dormitory's this way!" George gasped.
"Are... you... mental?" Isabella panted, pulling them through a secret passage. "The Owlery is right over here!" They burst out onto another corridor and dashed wildly along the passage. They slipped into the owlery, tripping over a few bones that lay on the floor. Isabella stopped and placed her hands on her knees, gasping slightly.
They waited for a few breathless moments, listening as feet pounded along the corridor. Argus Filch hobbled into the Owlery his jowls quivering with excitement and his face red with exertion.
"Aha!" he said triumphantly, pointing a crooked finger at the twins and Isabella. "Gotcha!"
"I beg your pardon?" Isabella asked, looking perfectly innocent and a little surprised.
"Don't play dumb with me girl!" Filch snarled, shuffling forward.
"I wasn't aware that I was playing anything, sir," Isabella replied, sounding calm and collected. "Are you looking for someone?"
"Rule breakers!" he cackled.
"I'm sorry, I haven't seen anyone by that nature," Isabella said. "Unless you mean those two," she jabbed her thumb at Fred and George.
"Wha'?" Filch was beginning to look confused.
"I just came up here to send an owl," Isabella lied smoothly.
"All right, where's your letter then?" he demanded.
"I'm afraid I've already sent it, sir." Filch blinked as though he had been hit over the head. George slipped his wand behind his back and out of sight.
"Oh, right then," Filch said, looking confused. His eyes were blank and slightly unfocused. He stood for a moment, at a loss of what to do, then turned and shuffled away. Isabella waited until she could no longer hear his mumbling, then she smiled at George.
"Nice Confundus Charm!" she complimented.
"You sort of inspired me," George grinned. "In a sort of not breaking the rules way."
"What did you mean, 'unless you mean those two'?" Fred asked.
"I was trying to distance myself from you," she shrugged. "It would be more suspicious if a Ravenclaw and two Gryffindors were together on purpose than by coincidence. Besides, Filch hates you. I was getting myself out of danger zone."
"Thanks for that," Fred laughed. Then his face darkened. "I wonder who she's caught..."
"Only one way to find out," Isabella said. "Give me a few minutes head start to get back to Ravenclaw Tower before you head off." She went to the door and peeked out before calmly strolling away.