“It’s called Tribal Dysmorphic Disorder.”

Applejack reached over and took her wife's hoof, chilled as it was from the medical center’s sterile air. Physical touch always helped the pegasus center herself and already she could feel Shy's heartbeat quickening with worry.

“It's when a foal of mixed parentage has a significant over- or under-expression of one or both parent's tribal traits,” Dr. Gentle Care continued. “It's not rare, but it’s much more common in unicorns where it's easily identified by stouter builds and weaker magic. Even then, many live ordinary lives completely unaware that they have it."

She thought she could almost feel the echoes of a second heartbeat in the river of her wife's, but that had to be her imagination. It was too soon. Shy wasn't even halfway along yet, her bulge still hidden under a knitted sweater.

"B-but— she's okay, right? Not in danger? Lots of ponies live with this and they’re fine?"

He winced. It was slight, but not slight enough for her to miss it. "I said many unicorns live with it. With the foal of a pegasus and an earth pony... things are more complicated."

Applejack tightened her grip, making herself a rock for Shy to anchor herself to. "Complicated. How?"

In response, he reached over to pass her a manila folder. Fluttershy snatched it first and flipped it open. There were charts. Numbers. A lot of long terms in medical jargon. Nothing that made any sense to her.

But Fluttershy's spiking pulse spoke volumes.

"Give it to me in plain Equish, doc."

He sighed. Removed his glasses. Cleaned them. Put them back. "According to these preliminary tests, it's highly likely that your daughter is going to have your bone structure—" he nodded to Fluttershy before turning his gaze "—and your musculature."

Her breath caught in her throat. A daughter. Her daughter. Somehow, it all hadn’t felt quite real til that moment.

“We can't predict the severity of her condition, but given the factors at play I’d project it to be near the extreme end."

She almost didn't want to know. "Factors?"

"The odds of severity increase when both parents are of particularly pure stock."

Her mind flashed back to a dozen Apple family reunions; every last one of them hornless and wingless until she'd married. She didn't know much about Fluttershy's extended family, but remembered her father-in-law once saying he could trace his lineage back to Commander Hurricane's aide-de-camp.

“In addition," he continued. "TDD is a known side effect of magically-aided fertilization. The spell has to make a few… logical leaps when transforming an egg into sperm, which can cause an overexpression of certain genes."

Fluttershy's pulse was like a frightened bird in her hoof. She squeezed and it slowed, slightly. "Doctor... please... how bad is… 'extreme'?"

He sighed, clearly resigned. "She'll be prone to exhaustion, overexertion. An inability to sense her limits leading to collapse and regular fainting spells. That’s the best case scenario. In the worst... in addition to that there's a very real possibility she might be strong enough to break her own bones. Even light foalish roughhousing could send her to the hospital."

The room fell silent. Shy's hoof was hot in hers, blood pounding.

Then it steadied. Slowed. Applejack spared her a glance. There was an unfamiliar hard look in her wife's eyes.

"Shy? Hun? What are you thinking?"

Fluttershy took a deep breath. Held it. Released it. Her hoof stayed gripped tight. "Applejack. You know I’ve witnessed a lot of births. Helped a lot of them along. I treat and help as many as I can but... Nature can be callous. It doesn't coddle. A bird with a misshapen wing. A snake with no eyes. They won't survive in the wild. Sometimes, you have to make a hard choice."

Shy's hoof burned against hers. Or was that her own blood running cold?

"Sometimes it's... kinder, to spare them the pain."

The words plunged like a knife into her heart. "Y-You can't be serious." The hoof stayed firm. Applejack recoiled, horrorstruck. "...No. No! This ain't some- some critter you picked up in the woods! This is a pony we’re talking about!”

“I know.”

“Our filly!”

“...I know.”

“And you want to kill her?!”

"I don't want to ki... to abo… I don't want to!" Shy snapped, her voice raw. "But what kind of life would she have?"

"Her life! Any life! One she can find her own way in! Doesn't she deserve the chance?!"

"What chance!? To spend her life in the hospital? Or indoors, protected, like some kind of porcelain doll? I wouldn’t want that for her!" For all the years they’d been married, she’d never heard Fluttershy so angry. Worse, she couldn’t tell if it was directed at her, or the diagnosis. "And what if she takes after you?! What if she wants to run and play and buck apple trees and do rodeos and we have to tell her 'no' because we decided she had to live crippled!?"

"We decided nothing! It's fate! Bad genes! Bad luck! I’m not letting you kill our filly cause she might have a tough time!"

“It’s just an option!” Fluttershy hissed, “One we have to consider.” Her voice solidified into something cold and hard. “But it sounds like you’ve already made your choice.”

“What choice is there to make? Between a disabled filly and a dead one?! There’s only one answer!"

Fluttershy was quiet for a moment.

Then she stood up, pushed back her chair, and let go of Applejack’s hoof.

“I think…” She shook her head. “I need some air. I’m going to Dash’s for… awhile.”

“Shy…”

“No! I can’t… I can’t talk to you right now.”

Fluorescent lights caught the glint of tears slipping down her face as she turned and left.

Leaving Applejack alone.

In a moment of terrible clarity, Applejack wondered if she might have just lost both of the most important mares in her life.

Her hoof was cold, clutching nothing but dead air.