Just a side note: when Sadie said Barty's name Y/n was under the Imperius curse. Her brain was so foggy that she doesn't really remember that much of it. The only thing she remembers at the moment is that Alastor kidnapped her in the maze and sent her to the graveyard before returning to Hogwarts.
"Y/n?" Severus spoke, pushing my hair out of my face as he held my body against his. Minerva stood over us, smiling as she saw my eyes open, taking in the scene around me.
"W-where's Harry?"
"I think Alastor took him for a walk," Minerva said.
"What?!" It was as if my instincts had kicked into overdrive in that moment. Adrenaline was coursing through my veins and any exhaustion I felt from the spell had turned into fear for Harry's life. I scrambled to my feet as Severus held my body upright. With a wave of my wand, the wound was bandaged, though I knew it wouldn't hold for long. I simply hoped it would stop the bleeding long enough for me to get to Harry.
"We have to go!"
"Y/n, what's going on?" Minerva asked.
"Something's wrong with Alastor! He's the one who took me to the graveyard! He Imperiod me to get me into the maze! Sadie took a strand of my hair and used polyjuice potion to become me. This was part of his plan all along!"
Albus, Minerva, and Severus looked horrified. We quickly ran toward the castle, finding the Dark Arts classroom quickly. I could feel my body fighting exhaustion, struggling against everything not to pass out. I took several deep breaths as Albus blasted the door to Alastor's office open, also blasting Alastor away from Harry and into a nearby chair in the process.
"Harry!" I ran toward him, pulling his shaking form away from Alastor and into a hug. Severus poured a vial of Veritaserum into Alastor's mouth.
"Are you Alastor Moody!?" Albus yelled. "Are you?!"
"No!" the stranger groaned.
"Is he in this room!?"
The stranger's eyes flicked over to a small trunk next to Harry and I. Albus moved toward the trunk and I quickly ushered Harry away from it. Severus looked behind him, making sure Harry and I were at a safe distance away before opening the trunk. I took a few steps closer and as we peered into a seemingly endless void we noticed a man at the very bottom, sitting in the darkness of the trunk.
"Alastor?"
"Y/n Y/l/n? Is that you?"
"Yes. Everything's going to be okay, Alastor. We'll get you up in a minute."
"If that's Moody then who's that?" Harry asked, gesturing to the man sitting in the corner of the room.
"Who are you?" I hissed. "Why pretend to be Alastor?"
"Don't use that name!" he hissed. "I've endured that name for far too long and hearing it again from your lips... it's sickening."
"Then what should I call you?"
"Oh come now, sweetheart. You don't recognize me even a little bit? I suppose I have played my role to perfection but I thought you of all people would have figured it out by now."
I thought back to what Sadie had called him and how he had spent so many years under the Imperius curse. I was angry with myself for not seeing it sooner.
"Barty?" I whispered, watching as a small smile spread across his face before it suddenly changed. His face contorted in pain, bubbles forming across his skin, black hair sprouting from his head. His hands gripped the chair so tightly it cracked from the pressure. He groaned as the transformation came to completion. Barty lunged forward, trying to get to Harry but I stepped in front of him.
"Still willing to get yourself killed to protect people. Isn't that right, princess?"
"Don't call me that!" I growled.
"Thought you'd be happy. I returned your father to you. I was about to kill the boy responsible for taking him away from you in the first place. All so you could have your family back and this is how you thank me?" he said, suddenly seeming more hurt than angry, though that hurt soon returned to anger. "The Dark Lord shall rise again! I'll be rewarded greatly for returning him, you'll see. Someday, I'll ask him for your hand in marriage and he'll remember how loyal I was to him. He'll promise you to me."
"You're insane!"
Severus moved next to me, wrapping an arm around my waist, only seeming to anger Barty more.
"No, I'm realistic! Where was Snape when your father needed him, huh?! He was nowhere! Your father is going to enjoy killing him."
"He was with me!" I yelled. "When I had no one! He was with me when I lost everything!"
"The reason you lost everything is standing right behind you!" Barty yelled, pointing an accusing finger at Harry.
"You leave him out of this!"
"You would defy your own family to protect the boy? You would go against everything your father believes in for him!" he yelled.
"Take Harry out of the room!" I ordered and Minerva quickly left with Harry as I turned back to Barty.
"I am nothing like my father and you people are not my family! Where were any of you when I needed you!?" I moved closer, my voice lowered and strained with anger. "Where was Tom when I was getting beaten everyday, huh?! Where was he when my uncle tortured me with the cruciatus curse? Where was he when my uncle threatened to murder everyone I cared about!? He's the one who left me with them!" I stepped back. "If he wanted to be a family he would have stuck around the first time! He can go straight back to hell!" My words hung in the air, a strange and uncomfortable silence falling around the room. Severus placed a hand on my arm as he had heard the words I'd hissed at Barty. His other hand held his wand, still pointed directly at Barty's forehead. I squeezed his hand before leaving the quiet room without another word though I didn't make it far before I collapsed in the hallway, the adrenaline finally wearing off as my body succumbed to its exhaustion.