Narcissa apparated in front of Gringotts and headed inside with an air of neutrality. She walked over to the goblin teller that handled the Black vault affairs, and waited for him to notice her presence. He peered over the counter and looked down at her with indifference. "What can Gringotts do for Madame Black today?" he said.
She smiled politely at him. "I would like to enter my family's vault to extract some necessary items," she said simply.
He nodded, stepped down from his station, and walked over to the back of the bank. "I will need to check your wand, just to make sure that you are who you say you are, Madame Black. Standard procedure and all that." She nodded down at him and handed him her wand without question. He looked at it for a moment then handed it back to her. "Alright, follow me Madame Black. I'll take you to your vault."
They headed down a stairwell that led further into the bank, then got on the trolley that took them deeper underground. When they reached the Black family vault, both of them stepped out and walked to the vault with their respective keys. They opened the vault together, since it was such a long standing account in the upper ranking vaults. "I'll be here awaiting your return Madame Black," the goblin said as he returned to the trolley.
She walked into the vault and sighed in frustration. She rubbed the ring to ask whether there were any books that would help them with the trials, and if so, where to find them. Soft whispers filled her head with the answer that there were books. Narcissa followed the ring's instructions.
She walked deeper into the vault when suddenly a patronus of an otter appeared before her and began to speak in Hermione's voice. "Narcissa, your sister has been possessed as part of the first trial. Unfortunately, she apparated away from Harry and me, so he's doing what he can to find her with the help of his Auror team. But I need you to come back to the manor as soon as possible as safely as you can. I don't want you to fall prey to Andromeda." The otter disappeared after the message played out.
Narcissa groaned in frustration, then took a breath and continued her search for the material that they might need. She collected the books she found, placed them in her bag with an undetectable extension charm, and headed out of the vault. She joined the goblin in the trolley and headed back up to the entrance of the bank.
Andromeda apparated into Diagon Alley, and upon arrival, she began to sing.
Dancing Bears
Painted Wings
Things I almost remember.
And a song someone sings
Once upon a December.
She walked down the alleyway while singing, causing the omegas around her to collapse in the streets. She continued to walk further down Diagon Alley, chaos ensuing around her. People began to scream as more and more omegas fell to the ground with no visible cause as to why.
Someone holds me safe and warm.
Horses prance through a silver storm.
Figures dancing gracefully across my memory.
Aurors apparated on the scene and began to quell the vast amount of chaos that was occurring. Harry and Ron arrived soon after and looked around for Andromeda since Harry suspected that she was the one behind all of this. He told the other Aurors that they were to try to subdue the subject because she was only doing all of this under the influence of someone else's control. The team broke off into smaller groups and spread out to find the suspect in question. Harry and Ron's group came upon Andromeda walking through the main thoroughfare of Diagon Alley.
Someone holds me safe and warm.
Horses prance through a silver storm.
Figures dancing gracefully across my memory.
The boys quickly jumped into action and began to cast spells to try to subdue her. The spells seemed to bounce off of her until Harry decided to cast a Silencio. He suddenly remembered Hermione talking about a soundproof room for her. She gripped her throat in confusion before turning and looking at Harry and his team. In a rage, she lashed out at them. With a wave of her hand, she sent them all flying back a few paces from her. She regained her voice and continued on her path, causing more and more people to either fall over or fly away from her.
Far away,
Long ago,
Glowing dim as an ember,
Things my heart
Used to know
Things it yearns to remember
And a song someone sings
Once upon a December
Harry quickly got up and began to run after her once more with Ron and the others jogging behind him. She turned down another alleyway and continued her rampage. She took another turn and headed toward Gringotts, leaving disaster in her wake before she spied Narcissa walking out of the bank.
The Bringer of Sorrows screeched at the sight of the Omega Prime, becoming more enraged. She started to run full force toward the blonde when suddenly Andromeda herself started to fight internally with the entity to protect her sister as best she could, slowing her body down in an attempt to give Narcissa time to escape.
"You cannot stop what is to come, witch. The Demon Overlord will rise no matter what the Alpha and Omega Prime do," the entity said in Andromeda's mind.
"You are not hurting my sister. I don't care what you are, YOU CAN'T HAVE HER!" Andromeda shouted internally. Harry finally caught up to her, casting another silencio and a petrificus totalus so that she froze in a full body bind. She fell to the ground, silent, and watched with tears in her eyes as Narcissa disapparated away. Harry, Ron, and two other Aurors rushed over to her, picked her up, and apparated away to the Ministry of Magic. They locked her away in a soundproof holding cell until they could figure out what to do with her.