There is a shift of the world under your feet, when you realize your husband is willing to kill your son. His son, yes, but your son.
Ursa has stood for years on a tilting planet, set shuddering by the moment of knowing, of seeing, that Ozai would. That Azulon would order and mean it and that Ozai would obey and that Zuko, her son, her child, would die by his father's hand.
And she has tasted for years the blood in her mouth, where she bit as she realized that above all, what coloured her husband's face was not rage, was not grief, but humiliation. Anger. Rage and resentment, that Iroh would be honoured above him.
That underneath all of it, there might even be relief, that Azulon had demanded Zuko's life, and passed over the girl to whom he was namesake.
Knowing these things changed everything; understanding them was like the burn of water cold beyond imagining, shocking her, choking and galvanizing all in one blow. It made her act: it made her understand, and it made her do, and it taught her everything in the world was sand and would shake apart at the slightest tremor.
In a world where a grandfather would order a father to kill a son, and the only thing that stopped it was that a daughter-in-law become a regicide, nothing could be trusted or taken for granted. This, she learned, all at once and forever.
So she survived.
Exile was only a stay of execution. Ozai's promises to the contrary were only words. Ursa nodded and murmured agreement, but she knew he only didn't throw the law at her, have her executed outright, because there were factions in the court who would be obliged to protest. They didn't really care enough to actively protect a regicide: none of them were close enough family for that, and besides, family was meaningless, as she'd just learned. But they would be obliged to make the show of protest, just to keep their alliances happy.
But to a fledgling Firelord, taking the throne out of turn after his father's death, when the cause is only kept quiet to keep the masses from rising up (so they said) . . . such a man couldn't afford to have any scandals to begin his reign.
So he would make a show of betrayal, and then one of love. He would exile her. Then she would be killed. Quietly. Some way he could plausibly deny, write off as an illness or a suicide out of shame. An accident. Everyone would make a brief, sad face, and then she would be forgotten.
It was self-evident.
So when the assassin came, he found an empty room and the folded robes of the Firelord's wife, and nothing else.
Hours before the assassin came, Ursa was already gone.
The wilderness, which she came to know very, very well over the months that followed, was not kind. And it was cold: it seemed to her she was always cold. Hungry, too, but hunger only turned into another kind of cold, and cold ate the world.
Ursa had never been cold before. Not this way. Not the cold that ate under the skin and made a home in the bones, so that even in the sun there remained a kind of chill, like the heat couldn't make its way past the skin. She'd been a little girl shivering as she emerged, just a little too late in the evening, from the salt water where she played. She'd been uncomfortable on the nights that crept their way towards the coolness of that water. She'd wanted a blanket, a robe, a familiar and beloved body beside hers to share heat.
But she'd never been cold.
Hungry was easier. Ursa would never have thought that, but it was. She knew enough that she could eke out things to eat, berries and edible flowers. It turned out not so hard as she'd expected to catch fish - not, at least, if you turn your shirt into a net. She ate the fish raw. She didn't have much of a choice: why would the wife of a firebending prince, or the daughter of a noble house, or the mother of two firebending children, ever need to learn how to light one of her own?
She lived for the thought of far-away fires, and what fire meant, and why she had done what she did.
She vaguely remembered lessons in astronomy, years ago, as a girl. Her father had felt it was very important; she'd considered it less important than figuring out which of the boys her age liked her, and which of them she liked back, and whether or not any of them were likely to be marriage-matches her parents would accept at all. So now there was only the vague shadow of a thought: there should be constellations she recognized, and ways of figuring out her direction.
Knowing that didn't help. Nothing in the sky was familiar. In the end, she drew her own pictures across the white-dotted blue-black expanse, and used them instead.
To her, the moon always felt cold, distant and accusatory: it lit up the woods as clear as day, made it harder to hide. Ursa wanted to get away, to make sure she was far into the Earth Kingdom before she tried finding anywhere to live among other people. Too close to Fire Nation anything, and she ran two risks: one, that her own people - no, those who had been her people - would recognize her and kill her, and the other that those from the Earth Kingdom who were on the front edge of conquest would recognize her from months-old portraits not yet torn down, and they would kill her. Or try to ransom her back. Or something equally unfortunate.
Better to get far away, where she could disappear.
She slept during the day. It was warmer. The light of the sun was a greater risk, but it came with that warmth; the moon was chilly, cold and heartless. The dimmer the moon, the safer she was.
And the brighter the stars.
Her own constellations weren't all grand, noble things. Beside the boar-hound and the sword she picked out the line of Zuko's favourite kite, and of Azula's first beloved pinwheel. She missed them both with an ache like someone taking a carving tool to the space between her ribs.
Ursa tried not to think about Ozai. The habits of love mixed painfully with betrayal, fear, hurt and hatred, and she didn't need more pain.
Her shoes left blisters on her feet for a while, until they toughened; her rough clothing tattered. Her hands roughened, and that was a slow relief, because until they did her palms were scratched, raw, blistered and bleeding. She hid so often that she did not burn, but the sun gradually darkened her skin, too, like any woman who worked out of doors.
She cut her hair shorter. It had tangled so badly she couldn't get it undone.
Ursa saw the moon darken three times, always walking under it, before she dared try to find any other thinking creature.