Andromeda's POV
"We need to learn the Patronus charm first," said Regulus.
"Just think of your happiest memory and cast," said Arthur.
Andromeda screwed her eyes shut and thought of the day she got her Hogwarts letter. She thought of her parents' faces, proud and happy. She thought of the excitement building within her, that she would go to the famous school and learn magic!
"Expecto Patronum!" A wisp of white smoke came out of her wand.
"Don't worry, nobody gets it on the first try," said Arthur. "What was the memory you used?"
"The day I got my Hogwarts letter," said Andromeda.
"That's far from strong enough," said Arthur honestly. "Try something involving people you love. That often works."
Andromeda thought of her mom singing her a lullaby when she was five. She remembered how warm and safe and loved she felt. "Expecto Patronum."
A large cloud of white fog emerged, but it didn't take a particular shape.
"We're getting close!" said Arthur excitedly.
Andromeda thought of sneaking into the Slytherine common room to talk with her sisters. She thought of the times they stayed up late into the night talking about anything and everything, and she thought of how much she loved Bellatrix and Narcissa. She felt a surge of warmth and love, and she yelled, "Expecto Patronum!"
A cat leapt out of her wand. She gasped. "It worked!"
"Which memory?" asked Narcissa.
"Those nights when I sneak into the Slytherine common room and we stay up late talking."
"I'll try it," said Narcissa. "Since it's a memory we shared, it should work for the both of us."
She took a deep breath and said, "Expecto Patronum."
A matching cat leapt out of her wand. "Yes!"
They high fived.
Soon, everybody else was working hard at getting their patronus to come. Regulus ended up casting a swan, while Bellatrix and Sirius shared the dog patronus. Mare watched in fascination. Andromeda directed her patronus towards her, and Mare reached out to pet it. The cat actually purred when she did.
"I guess we should practice some other things now," said Arthur.
For the next hour, Andromeda sharpened her defensive skills.
"Who wants to be my target?" she asked. "I need to practice on something."
"I will, but go easy on me," said Bellatrix.
"I make no promises," Andromeda joked. "Congelo!"
Bellatrix wheezed as the ice curse hit her in the chest. Andromeda was about to apologize when Bellatrix hit her with a tickling jinx. Andromeda started laughing uncontrollably.
"Not fair," she giggled.
"Oh, yes, it's fair," Bellatrix laughed. "Finite Incantum."
Andromeda sighed with relief as the curse was lifted.
"I think that's enough for today," said Regulus.
They turned to look at him and gasped. He was clad in a metal suit.
"What are you wearing?" asked Andromeda.
"I transfigured my clothes into shock proof armor so that Mare would have a target to practice her lightning on."
Mare threw another lethal bolt at him.
"See? It doesn't even hurt."
He flicked his wand and turned his clothes back to what they were before.
"So we're done?" asked Narcissa.
"Yes," said Regulus.
She brandished her wand excitedly. "If we practice like this every day, nothing can stop us," she remarked.