The earth pony bites her lip as she's led into the Royal Throne-room by a white royal guard. She bows at the regal, white alicorn, making sure to do it properly.
"Bon Bon," Princess Celestia nods, looking down at her from the grand seat.
"PLEASE EXIT THE ROOM TO GIVE US SOME PRIVACY!" Princess Luna shouts in the Royal Canterlot voice. All of the guards head outside, and the earth pony covers her ears.
"You too, Luna," Celestia says to the princess of the night.
"But, sister, all of Equestria's affairs are mine, too-" Luna begins, but Celestia cuts her off.
"This does not concern all of Equestria."
Luna opens her mouth to speak, but decides against it. She stands up and slowly walks out the back exit, muttering something that neither of the other ponies in the room could hear.
All the doors are surrounded in a yellow glow and are slammed shut. Then, all the sides of the room are coated in the same color. The earth pony looks up at her Princess, confused.
"This way, nopony outside can hear us," Celestia informs her.
"Oh..."
"Now, we have something very serious to talk about, Agent Sweetie Drops."
"Yes, Princess."
"When you were told to stay undercover in Ponyville, you were told to do so no matter what. Correct?"
"Yes, Princess."
"But what did you do, Sweetie Drops?"
"I... I told somepony I was an agent, your majesty."
"Why did you do this?"
The agent considers lying, but decides against it. "Because she was my best friend."
"That is not a good reason, Sweet."
"But isn't friendship supposed to be magic?"
"Of course, I'm sure everypony in Ponyville knows that - including you. But some friends need to keep secrets."
"But... Is she right?"
"About what, Sweet?"
"She said our whole friendship is based on a lie."
"Is she really your friend, Agent Sweetie Drops?"
"Of course she is!"
The alicorn doesn't respond.
"...Right?"
"Sweetie Drops. I am truly sorry to inform you of this, but whoever your friend is, she will have to be... eliminated."
"Celestia, you can't mean..."
"Yes, Sweet. I'm very sorry it has to be this way. And, you must... get rid of her yourself. Doing otherwise is punishable by death."
The earth pony doesn't respond, but she does begin a silent cry. Celestia walks down to her from the throne.
She strokes the mare's mane. "Can you do it, Agent?"
Sweet sniffles a little. But, wiping her face with her hoof, she looks up and says, "Can I sleep on it?"
"Of course. You may spend the night in the castle."
"Thank you, your majesty."
As soon as Celestia lowers the barrier of silence, Luna flies in through one of the doors.
"Finally, sister!" she rolls her eyes, "It's past time for you to lower the sun."
"Oh! I do apologize, Luna. Wait here, Bon Bon. I will lead you to your chambers in a moment."
The alicorns fly off, leaving Sweet alone in the Throne Room. She reaches into her saddlebag and pulls out a picture of her and her best friend, sitting on the bench like they always do on Sunday afternoon. Pinkie Pie had jumped out of the bushes with a camera that day.
"Lyra..." -a single tear falls onto the edge of the picture- "...why does it have to be this way?"
"Hey, Bonnie!" Lyra smiles as her favorite earth pony walks inside.
"Don't call me that," Sweet replies.
Lyra frowns, "Oh, do you want me to call you Sweetie Drops?"
"NO!" Sweet screams, "Just... Call me Bonnie! That's fine!"
Before Lyra can reply, Sweet runs upstairs and into her room, slamming the door behind her. The unicorn stares at the stairs for a minute, laughs when she thinks about what she's doing, then closes the door and returns to cooking the rest of Sweet's special, imported oats.
When Sweet walked downstairs, she could smell a wonderful aroma coming from the kitchen. She trotted in to see Lyra cooking some tasty-looking oats.
"What'cha making, Lyra?" she asks, looking over the mint-green mare's shoulder.
"Oh!" Lyra jumps, pushing Sweet back. "Uh... Just oats! Just ordinary oats! Ordinary oats I bought at the store!"
Sweet shakes her head, "You're such a horrible liar."
Lyra pouts.
"Those are my special oats, aren't they."
The unicorn nods.
"I thought you ate all of them?"
"I found more," Lyra admits.
"I want some," Sweet says, pulling a glass plate out of the cabinet.
"You're not mad?"
"Of course not! I mean, what if this is... the last meal we ever have together?"
"Um, what do you mean by that, Bonnie-Bon?"
"...Nothing. Never mind."
"Well, okay?"
Sweet makes an artificial cough. "Oh! The oats are ready, Lyra!"
Lyra smiles and splits the cooked oats in-between the two of them.
"Are you ready to eat?" Lyra asks.
"Hold on," Sweet says. She trots into the bathroom and closes the door behind her, then reaches into the closet and pulls out the rat poison they bought when there was an infestation (much to Fluttershy's dismay).
She looks at the bottle of liquid, and considers pouring some into Lyra's drink. Or drinking it herself. But what would Lyra think if she walked into the bathroom and saw her roommate dead, with a bottle of rat poison in-hoof?
No, she couldn't. But she couldn't kill Lyra, either. Not now, at least. In fact, the thought of killing Lyra filled her with too much guilt.
She places the poison back and walks back into the kitchen.
"Here you go, Bon Bon!" Lyra places a plate of oats on the table for her friend. She had already set down her own.
"Hey, Lyra?" Sweet asks mid-meal.
"Yeah?"
"What if..."
"What if what?"
"Well, what if you weren't here tomorrow? What would you want to do?"
"I wouldn't leave your side."
"...Really?"
"You're my best friend, Bon Bon! All of my other friends live in Canterlot."
"You have friends in Canterlot?"
Lyra nods, "I used to live there. You didn't know?"
Sweet shakes her head.
"Huh. Well, maybe you can meet them sometime."
"Okay."
"By the way, where were you yesterday?"
"Oh... I was, um at..."
Lyra gasps, "Bonnieeeee! You got laid, didn't you?!"
"What?!" Sweet's face turns red, "No! Of course not!"
The unicorn giggles, "Who was it?"
"I said I didn't!"
"Oh, sure."
"I was in Canterlot. Uh, visiting my family!"
"Yeah, yeah. Hey, did you get Prince Blue Blood? Lucky mare!"
"S-Stop!"
Lyra rolls her eyes, "Alright, alright. I believe you."
"Thank you, Lyra."
"Not."
"What was that?!"
"Nothing!"
"I'm gonna get you!"
Sweet stands up and starts chasing Lyra around like they were fillies. They both smile and laugh, and eventually, the chase travels outside. The earth pony feels nearly carefree - almost not thinking of her duty as Agent Sweetie Drops. But it was still tugging at the back of her mind, and she knew it would never stop.