“Ow!”
“Oh, I’m terribly sorry, darling.”
Twilight twisted around to look at what Rarity was doing. She understood that there were pins involved in fitting a dress, but that had hurt. “Why is this thing so pointy?” she demanded, gesturing to the shards of crystal embroidered along the edges of the dress, which had jabbed her in the side. “I’m not sure dresses are supposed to be sharp.”
Rarity waved her off, a half dozen pins floating in her magic and slipping through the dress as she worked. “I assure you that once the fit is right you won’t even notice. Just have to get everything to lay correctly, my dear, and you’ll be the talk of the evening.”
Twilight rolled her eyes. “It’s a diplomatic meeting, Rarity, not a ball.”
Rarity hmphed. “Well. Still.” She pulled back, examining the alicorn critically, and then sighed. “I suppose that will do, then. You can take it off, now.”
Twilight nodded, and pulled the dress off over her head - or rather, she tried to. A sharp hiss of pain left her mouth and abruptly she teleported two feet to the side instead, twisting to look at her side, where a gash had opened up, trickling blood. “Rarity!” she scolded, before her horn lit, she concentrated, and the wound closed itself as if it had never been. “I swear, if that thing cuts me while I’m in Griffonstone, I’m going without it.”
Rarity turned somewhat red. “I assure you it will not,” she insisted, having the grace to sound embarrassed. “Besides, they’re griffons. They’d probably love a dress that doubled as a weapon.”
Twilight was not impressed. With a hmph, she walked out.
Some hours later, Rarity had finished her adjustments, and was giving the dress a final inspection, just to make sure it was perfect. Somepony with a less critical eye probably would have passed it, too. But Rarity was more thorough than that, and she gave the dress a disappointed frown when she found it. In the gap between two of the crystals, a line of dried blood. It was on the inside of the dress - you certainly wouldn’t be able to see it without getting entirely too close to Twilight, but it was a blemish. A discoloration. An imperfection, that she could not have.
The dress wouldn’t survive the kind of wash needed to get out blood. With a sigh, Rarity looked at the clock. If she stayed up all night, she should have time to make a replacement. And at least this dress had served to get all the measurements correct. She put it back on the rack and turned to her remaining crystal supplies. Time to get back to work.
Rarity woke at noon the next day. It took her a moment to open her eyes, but when she did, the midday sun was quick to snap her into full wakefulness. The dress! She didn’t remember going to sleep, had she even finished it? Dashing downstairs, she opened the door to her boutique, and stopped.
Under her work table, the replacement dress was a mess, torn in two pieces with shards of gemstone flung halfway across the room. But she hardly had eyes for the ruined piece of work, because in the middle of the room was a dress of pure magnificence. It had the same lines as the dress she had been working on, yes, but it was grander, sleeker, more colorful. Somehow it seemed larger than it had been, even though she knew it would still fit Twilight perfectly. “How…?” she murmured, stepping up to it reverently. Her hoof reached out to touch it…
“Ah!” she pulled back as a crackle of electricity shot out from the dress, making the room smell of magic. Not her magic, though - she would know that purple color anywhere. Hesitantly, she approached again, and this time the dress did not shock her. She turned the hem of the dress up, somehow knowing what she would find.
The stain of blood was gone.
At first, Rarity pretended the incident was a happy accident. Twilight was ecstatic about the ‘improvements’ to the dress, it didn’t stab her anymore, and by the time her trip to Griffonstone was over, she had forgotten about the fitting incident entirely.
But Rarity couldn’t forget. She’d tried to recreate the phenomenon with her own blood, but all she had managed to do was ruin a perfectly good design. Her blood wasn’t enough. She couldn’t remember if Twilight had ever bled in her presence before - was it just because she was such a skilled spellcaster, or was it because of her ascension? Rarity didn’t know, but it didn’t much matter. She needed to see if it could happen again.
It was weeks before she got another chance. A monster from Tartarus got loose - something to do with Cozy Glow and a new pen pal at school. Rarity was fuzzy on the details. But during the fight that had arisen, Rarity saw it cut Twilight. Not enough to seriously hamper her, but enough for a sample, for an observant unicorn to collect later that night.
A dab went on a new dress design. Another dab on her spare sewing machine. A few more on choice pieces that she wanted to use in future dresses. And then, despite being too excited to think sleep was possible, she retreated to bed.
She awoke surprised to realize she had fallen asleep at all. Approximately two seconds later, she was downstairs again. “Oh… my,” she breathed.
It had worked. Everything had worked. The dress was resplendent, the sewing machine sleek and twice as powerful as before. Each individual piece of jewelry and fabric was gorgeous and beautiful and perfect. With a soft laugh, she realized she had opened up a gold mine. All she had to do was make one of her best friends bleed.
There was a moment of doubt. Surely that wasn’t worth it. But then, her eyes fell on one of her sewing needles. It had been the one in the sewing machine when she had left it for the night. Carefully, she picked it up in her magic, admiring its tiny, perfect point.
She had to have more.
