Supernatural Little Sister

Lost Part 2

"This...is where we live?" Allison asks, in awe of the huge bunker.
"Yeah, is anything coming back to you?" Sam asks as he leads her down the stairs.
"No." She sighs. "Holy hell! Cas, don't do that." Allison screams as Castiel appears in front of her.
"Hello, little one. I am glad you are okay." He says and hugs her.
"Y-you called him Cas!" Dean says.
"I guess I did." Allison says. "For some reason, I just know him."
"Sit down here and I'll soon see everything you remember." Castiel says.
"How?" Allison asks but suddenly falls to her knees in pain. "Dean!" She utters, holding her own head. The brothers look to each other worriedly and Dean goes to her. The pain soon subsides and Castiel helps her up.
"Rest." He says, sitting her in a chair.
"What's wrong with her, Cas?" Dean asks, his voice breaking.
"My best guess is that someone attempted to wipe or alter her memories, and they didn't do a very good job of it." Castiel says.
"Who would do that?" Sam asks.
"Angels, probably. Let me take a look." Castiel says and approaches the drowsy Allison. "This will hurt." He says and places his hand on her head.
"Real comforting, Cas." Dean says. Both of their eyes start to glow a silvery blue and Cas grimaces as he looks through Allison's memories. The light suddenly stops and Allison's head drops to her chest, unconscious. Castiel stumbles to a chair and sits down.
"Oh, dear." He says rubbing his eyes.
"Cas, what is it?" Sam asks.
"I believe I could be of some assistance." Naomi says from behind them.
"You, bitch! You angel assholes did this to her!" Dean yells.
"It was only necessary, Mr. Winchester." She says. "I needed a bargaining chip." Naomi holds out a glowing blue vile. "The girl's memories of you two, right here." Castiel looks to her and sighs.
"In exchange for what?" Dean asks.
"Dean, don't do it, whatever it is. You can form new memories with her." Castiel says.
"I've lost her, Cas! It'll never be the same!" Dean cries. "What the hell do you want?" Dean yells at Naomi.
"The angel tablet, and the prophet's location." She says professionally. "Then, you boys will have your sister back." Castiel stands up and looks at the boys.
"How bad is it, Cas? Is it everything?" Sam asks.
"Everything about Sam and Dean Winchester is wiped from her mind. Every hunt, every laugh, every hug. You two never existed to her." Castiel says.
"It was quite the task. So, naturally a few other memories went missing and we had to install some false ones to fill in the blanks. You two were everywhere; you were her everything." She says and the brothers scowl.
"Stop saying 'were'." Dean growls.
"That's all you are, Dean. You were her big brother. Now, you're just some guy." Naomi says. "No more milkshakes and funny faces at LuLu's, huh boys?"
"Shut the hell up!" Sam yells. "We're not gonna do it, no matter what you say. Just leave." Sam says.
"Of course, I have another offer." Naomi smiles.
"What?" Dean asks.
"I need an assistant up in heaven and Castiel is the perfect candidate. You give me Castiel and I'll give you the memories." She says.
"No—" Dean starts.
"I'll do it." Castiel says.
"Cas—" Sam says.
"You need her." He offers them a sad smile. "But, after I say goodbye, they forget that I ever made this deal."
"What?" Dean asks.
"So you don't come looking for me or try to save me, Dean. There's no breaking this deal, for Allison's sake." Castiel says and Dean nods.
"Here are her memories." Naomi says and Castiel implants them into Allison's head. She slowly awakens as the memories flood in.
"Dean! Sam!" She smiles and hugs her brothers. The siblings share a warm, relieving embrace. "Cas! I don't know what the hell you did, but thank you!" Allison says and brings him into the hug. Castiel smiles and enjoys the last few moments with his humans.
"Tick-tock." Naomi says.
"Alright. Off I go." Castiel says.
"Wait, what? Where are you going? What's going on?" Allison asks.
"Don't worry. It's over now." Castiel snaps his fingers and the Winchesters drop to the floor, unconscious.
"Goodbye."