Y/N laid peacefully on the forest floor, completely motionless.  Her eyes were closed, and I couldn't tell if she was breathing or not. 

Dipper ran up to her, myself close on his heels.  "Is she okay?!  God, let her be okay."

He paused and listened.  "Grauntie's alive.  She's breathing fine."  Dipper paused and frowned.  "Like, she's not having any trouble at all.  Y/N's healthy."

I did a double take.  Glancing at Y/N's left wrist, I saw a familiar prosthetic attached, fully functional.  My mind reeled.  "All of his weirdness has been undone.  Every single thing." 

As if on cue, Y/N slowly opened her eyes.  "Wha-"

I impulsively hugged Y/N with all my might.  "Y/N, you did it!  You saved us all."

Y/N stared back at me with no recognition in her eyes.  "Oh, uh, hey there... sir.  Do I know you?"

My heart stopped.  "Y/N?  Don't you remember me?  Don't you remember anything?"

Y/N glanced over her shoulder, looking slightly freaked out.  "Who are you talking to?"

"Y/N!  C-C'mon, it's me, Stanford!" 

Stanley gently pulled me off of her, like he was dealing with a wild animal.

"Y/N..." I whispered, all of my hurt and pain going into the one word.  She was gone.  Y/N was really gone. 

Stanley pulled me into a hug, but I stayed statue still, numb with grief.  I mumbled, mostly to myself.  "She has no idea, but she did it.  She saved the world.  She saved me."

"I know, Sixer.  I know."

I offered a shaking hand to Y/N to help her up.  She hesitantly accepted, eyes flicking everywhere, taking in everything.  "You're our hero, Y/N."

We all trudged back to the Mystery Shack in silence.  I had to lead her back by the hand, like a lost child, on the road she had walked countless times before.  No one could bear to look at Y/N.  I caught Mabel glancing back twice, and bursting into tears each time.  Bill was gone, this was supposed to be the happy ending.  But without Y/N, no one was in the mood celebrate. 

We eventually reached the crest of the hill, the remains of the Mystery Shack barely staying together. I pushed open the decrepit door, letting light filter into my destroyed home. Y/N ran her robotic hand over the faded yellow chair, lost in thought.

"Do you really not remember anything, not even a little?"

She slowly shook her head. "I don't even know my name.  Y/N, you called me?  But still, the déjà vu is overwhelming. I know this place. You know how a word gets stuck on the tip of your tongue? It's like that with my life. It's just not there."  Y/N sank into the chair in hopelessness. 

Dipper hung his head.  "We saved the world, but what's the point? Grauntie Y/N's not herself anymore."

Mabel glanced around in denial.  "There's gotta be some way to jog her memory.  I know my Grauntie's in there somewhere."  She grabbed her scrapbook off the floor and flipped through the pages. "This'll work!  This has to work!  Here's the first day I met you.  You were really cool, but kind of scary.  And here's a macaroni interpretation of my emotions." 

Y/N flipped through the pages slowly.  "I'm sorry. I don't know what this is or who you are or-"

Waddles, long forgotten by us, jumped into her lap. 

"Aack!  Get off of me, pig!"

He jumped down and whimpered at her feet.  She sighed in defeat.  "Look, I'm sorry, but I don't think any of this is helping.  I didn't know my own name two minutes ago.  I don't think there's anything you can do."

A soft knock on what was left of the door startled us all. Fiddleford quietly walked in, his hat in his hands. "Stanford, I need to talk to ya. In private.  It's urgent." 

Stealing one last wistful glance at Y/N, I followed him into the kitchen.

He placed his battered hat on the table. "I need to see that memory thingamajig."

"You're bringing this up now, of all times?!"

He pushed his glasses up his nose angrily. "Watch yer mouth, Stanford. I need ta see if there's a possibility of bringing Y/N back."

I slammed the copper gun on the table, ignoring the excessive force. Fiddleford examined his creation, pressing a button in the back to reveal a panel I hadn't noticed before.  Carefully, he removed a roll of camera film from it.  He slid it into in oddly shaped glass tube and scribbled on the container. 

"Y/N's memories?!  All we have to do is play those, and she'll be herself again!  Right?"

My old friend shook head, remorseful.  "Theoretically, yes.  But this is what I was afraid of."  He turned the vial over in his hands.  "The doggone triangle's not dead, he's trapped in her memories, helpless.  The only way he can escape is if they're played again."

"So you're telling me-"

"Y/N won't be able to remember anything, Stanford.  The only reason I remember my past is with my own memories played out, and things are still hazy in some spots.  I'm sorry.  There's nothing we can do.  Y/N's gone.  She deserved a better end than this."

I stayed silent and stared across the hallway into the living room.  Y/N held her head in her hands while Mabel rambled on and on about the summer, trying to provoke a response. 

I felt despair wash over me with ice cold fingers.  No.  I couldn't let this happen.  I didn't come so far to lose to badly.   Fiddleford said she would any come back if her memories were shown to her, and if we did that, Bill would return, and everything Y/N sacrificed would be worthless. 

"... what if it was someone else's memory?"