Tis the king's idea

"Maybe," you reply, poking at your food as if considering a weighty question. You make sure to act as if this bothers you. Doe doesn't immediately bite your head off for taunting her, so that's a good sign. "There are actually a few possibilities."

"Oh?" she asks, crossing her arms.

You put down your spoon and look at her. "I'm a mage and I took you as my own captive before all this, so I could argue that you're exempt... But then, at that point you'd be the only one among your friends who isn't transformed."

She glowers and then looks away. As you expected from a good commander - she'd probably be even more put out if she somehow avoided the punishment through special treatment.

"There's something else too," you say with a sigh. "They're still looking for the person who actually poisoned the horses. Even with the communal punishment they'd still like to make an example of the person most responsible. And if they can't find the one who held the poison..."

"It falls to me," she says, matter of factly. She square her shoulders and says, "As a knight and a minor member of a noble family I hope that I will be killed with a sword rather than an axe."

You didn't know she was a minor noble, but it explains her attitude and post a little. "Ah, not exactly. With how successful the centaur transformations proved the king has really developed an interest. He thinks it's a far more effective deterrent than execution was." That catches her off guard. She was prepared for being changed into a centauress or killed outright, but you've opened the door to all kinds of possibilities. "Do you want to know?" you ask, trying to sound like a friend but knowing she's the type who will want to face their doom.

Doe nods and steels herself.

"One idea was to cross you with a cow. Someone to provide milk and cheese for the army, or maybe act as a wet nurse."

She looks like she's ready to stab you with a fork.

"I think that plan is out of the picture, overtaken by other ideas. Another popular choice since they felt you were a stubborn enemy was an ox, so you could pull bigger carts." That gets her even angrier, of course. "But recently there's been a focus on making the transformation 'thematic'."

"And what does that mean?" she growls.

"The horses were injured by poison, so some kind of creature that poisons is now the main thrust. Spiders, scorpions, wasps, lizards, frogs and of course snakes."

"Wasps!" she says with a shiver.

"Yes, though I'm the one most against that. If nothing else it would be hellishly hard to do."

"That's your problem? That's all you care about!"

"No, no!" you reply, "Hard to do also means it's likely to kill you. Painfully."

"Yes, cause you're on my side. Is that it?"

"Well..."

"You've been butchering my friends. Turning them into abominations!"

"I can't exactly stop the king. And that poison did wipe out so many of our horses that it caused a real problem. A lot of councilors called for executions."

"Aww, can't invade any more countries without your precious cavalry?"

"I was around when the duke of Ancarte threw down the gauntlet. I know my country starts a lot of wars, but this time I was there in person to see one of your dukes try to **** a prince." Before she brings up one of the many older border disputes you add, "I bet you can list off a dozen old grudges that might have made him do it, but he served up the perfect reason for our king to attack. With full support of our people and even the church."

That does put Doe back in her seat a bit.

"I had been thinking about trying this with volunteers, before this incident with the poison. It might have been a way to help people with certain kinds of injuries or conditions to recover - just not in their original form. The king probably remembered some conversation between myself and some of his councilors." It's mostly bullshit, of course, though at this point you probably can one day help some people with what you've learned.

You continue, trying to sound conflicted, "So I do feel at fault in some ways. Though it was a bit of a blessing that I had done some research beforehand, it meant my first attempts weren't gruesome failures. Anyway, it doesn't really matter what I want. As far as what happens to you all I can hope for is to either convince them to pick someone else as their scapegoat or at least get them to choose a transformation that you'll survive. Maybe even something you can come to like."

You quickly lock her away in her 'guest room', leaving the impression she may have rattled you. It takes time to slowly drip doubt over someone's thoughts, but you're pretty good at it. Since she's cut off from the rest of the world it should be easier to make her depend on you, appreciate you, and then more.