Okay, now I'm really worried. Something is seriously wrong with Rarity.

I went to visit her at the Carousel Boutique today, and Spike came along (obviously). I let him do the knocking, and when Rarity opened the door, the color instantly drained from his face.

"Rarity! Y-your, your..." he stammered. Of course, I immediately looked at Rarity and I didn't see what he was getting at. Her manestyle was a little different, like when she had to cover up her missing eyelashes that one time, but that's all I could pick out.

Rarity smiled and said, "My little Spikey-Wikey!" Then she bent down and kissed Spike directly on the lips. And not a peck, either, but a genuine, soft, slow, romantic-looking kiss! Not with tongue or anything horrible like that, but I was still floored. Spike stopped paying attention to everything around him and just stared into space, dumbfounded. I was about to firmly remind Rarity that Spike is a baby dragon, not to mention practically my little brother, but that's when I finally noticed it. I craned my head down slightly as Rarity lifted her head back up.

I couldn't see her horn. Her bangs were hiding the base of it, but they couldn't hide the entire horn: it should have been poking through her mane by at least half a decimeter.

"Rarity, did... did something happen to your horn?" I whispered, in shock.

She laughed. "Oh dear, I'm afraid so. It's... rather embarrassing, actually. I got it stuck in something I was working on, a metal dress form if you must know, and well, it snapped right off at the base, just like that. But don't worry, horns grow back quickly enough." She smiled gently at me. My poker face is almost as bad as Pinkie Pie's, so I'm sure she could tell I was highly skeptical of her story.

"You need to see the doctor, Rarity. There's no way you could snap the entire horn off without getting a concussion in the process, and you could have a hairline fracture of the—"

She giggled and placed a hoof to my lips, shooshing me. "Twilight, dear. Really, I'm fine. I've already been checked out. It's just blind luck, though I suppose you have placed a more positive spin on it than I did, initially. It could always be worse, right?" Rarity lifted her bangs to reveal the base of her horn, scarcely a centimeter or so long, and she did it without so much as a blush. I could immediately tell she was lying, because the osseous tissue had been sheared perpendicular to the grain. (You would think more unicorns would know about these sorts of things.)

"It doesn't quite look like a break, actually," I said, testing the waters. Rarity immediately dropped her bangs back into place. She looked flustered.

"Oh, well, of course, but I've, er, filed it down to remove the rough edges." Bald-faced lie. There were hard edges on the circumference, and Rarity is an accomplished artist and beautician. She'd never leave her horn looking like a tree stump. None of this added up.

"Aren't you worried about being able to complete your orders on schedule? You can't have enough horn there to focus magic," I asked, prying a little further. It made no sense. There is no possible way Rarity could lose her horn and not throw an enormous drama fit, I mean, it's just not her.

"Twilight! Honestly, it's okay. Yes, I am working at half speed, but it gives me a chance to practice my hoof skills. I was designing dresses long before I could use magic to speed up the process, dear."

"Ooooookay," I said, not really hiding my disbelief. "I guess if you're sure you're alright... But, please, don't hesitate to reach out to your friends for help if you need any. That's what we're here for. Promise?"

Rarity did the motions of a Pinkie Pie Swear, and I copied them. Then she apologized for being so busy, and shut the door right in our faces. Spike was still zoned out and drooling a little out of one side of his mouth, so I had to carry him back to the library.

On the way back, I briefly wondered whether Rarity could have been a changeling; but I quickly dismissed it as impossible. Her actions might be completely out of character, but too much of it sounded and felt like the real Rarity. A changeling wouldn't know half that much about Rarity's daily routine, let alone be able to do a Pinkie Pie Swear correctly. It was definitely her, but she wasn't embarrassed about what should have been by all accounts the worst possible thing, just oddly nervous...

Now I'm absolutely certain. Something very strange is going on in Ponyville, and I must get to the bottom of it.