What "unspeakable conclusion" was Amira's father about to reach?

Question

The short story "Seasons of Glass and Iron", winner of the 2017 Hugo Award for Best Short Story, may be read in full here. I just read it last night, and a single passage confused me, in the story of how Amira came to be on her glass hill:

The king’s daughter read an unspeakable conclusion in her father’s eye, and in a rush to keep it from reaching his mouth, said, Suppose you placed me atop a glass hill where none could reach me, and say that only the man who can ride up the hill in full armor may claim me as his bride?

What was this "unspeakable conclusion"? It can't be to marry her off to some prince, as he'd already said this was impossible for political reasons - nor can it be to put her on the glass hill, since that was her proposal to forestall him.

Answer 1

Expanding from my comment. Warning for disturbing themes and also a lot of links to fairy tales.

"Seasons of Glass and Iron" pulls from several fairy tales. It looks to me that variations on The Princess on the Glass Hill, The Enchanted Pig, and The Black Bull of Norroway are most prominent--however, there are references to many others scattered throughout. Tabitha thinks of her brother with winged sandals, and of women forced to wear "shoes of glass; ... shoes of iron heated red–hot." Amira references "words of desire [that] tumbled from men’s lips like diamonds and toads," and "a story about nettle shirts thrown up to swans." Therefore, I think it's reasonable to look at other fairy tales for inspiration as to what the king and Amira could have meant.

Here's what we know his requirements are:

• Amira get married
• Amira stay nearby so the king can keep an eye on her
• He (the king) not be forced to choose a husband from the neighbors, for fear of showing favoritism or upsetting the political balance

He also doesn't spin Amira's "ball so the men can find husbands" suggestion into a competition for her hand--in fact, Amira is the one who brings up the idea of her being a prize in a contest. So, what could he mean?

My suggestion (though it's a guess only, of course): the king could marry Amira himself.

This meets all his requirements, would almost certainly be considered "unspeakable" by Amira (and disgusting by Tabitha, when she reacts later), and is a motif found in several other fairy tales. Donkeyskin and The King Who Wished to Marry His Daughter are two of the most prominent, but there are a variety of stories that involve this--usually because the daughter is the only one beautiful enough to fulfill some sort of condition. However, as this story is pretty explicitly about the patriarchy and various people's roles in it, I think it makes sense that the king's reasoning would be changed a little here, especially as he's shown to take pity on and emphasize with the men re his daughter's "irresistibility," as well as to meld with the other tales more seamlessly.

Answer 2

It's worth noting that the story heavily implies that Amira is lesbian. It's absolutely explicit that she finds the idea of a (heterosexual) marriage "monstrous".

Note how her previous ideas, before "chose me a prince," let her avoid marriage entirely. And even "find me a prince" could be a purely political marriage. So really any conclusion forcing Amira into any marriage, is pretty much "unspeakable."

While Kitkat's answer is excellent, and the threat of incest may well be implied here, I think that option dulls the very open criticism towards power dynamics we consider far less shocking. The keys to the portrayal of Amira's story, in my eyes, are:

Once upon a time there was a rich king who had no sons, and whose only daughter was too beautiful. She was so beautiful that men could not stop themselves from reaching out to touch her in corridors or following her to her rooms, so beautiful that words of desire tumbled from men’s lips like diamonds and toads, irresistible and unstoppable. The king took pity on these men and drew his daughter aside, saying, Daughter, only a husband can break the spell over these men; only a husband can prevent them from behaving so gallantly toward you.

When the king's daughter is threatened with rape and harassment, the king takes pity on the men, and lays full responsibility on the shoulders of the daughter.

And this simple aside:

The king’s daughter, who did not want a husband

A categorical statement. Not "didn't wish to marry against her will," but rather "did not want a husband," any husband.

The horror of this sub-story is the way harassment and rape are considered "inevitable," and "the woman's fault," that she is held responsible for "fixing" the situation regardless of the cost to her. (And, let's be honest -- marrying, in such a society, would be little protection indeed; maybe looking more proper outwardly, but not actually keeping pawing arms off of her.)

This kind of horror doesn't need incest to make it worse, or anything else that isn't already clearly laid out. The situation itself is the horror; succumbing to it is unspeakable.