House Butterwell
Dairy lords grown rich enough to raise Whitewalls, the milk-white marble palace by the Gods Eye that men call the Milkhouse. Lord Ambrose Butterwell was Hand of the King once, briefly and badly — and his second wedding gathers every disappointed lord in the riverlands under one gleaming roof.
The fuller tale
Dairy money built Whitewalls, and dairy money is exactly the kind of wealth that makes prouder, older houses sniff — which may be why Lord Ambrose Butterwell built his new seat on such a scale, marble walls the pale color of cream rising by the Gods Eye until the smallfolk simply called it the Milkhouse and meant it half as a compliment, half as a joke about where the money came from.
Ambrose's own career gave the joke extra material: he served briefly as Hand of the King, and by every account not well, a stint remembered less for any particular disaster than for a general sense that the job had outgrown the man doing it. Whitewalls, in that light, reads as a very expensive attempt to be remembered for something else.
His second wedding, to a daughter of House Frey, was meant to be that something else — a grand match, a grand tourney, a dragon's egg offered as the joust's prize, every disappointed lord in the riverlands invited under one gleaming roof to celebrate a dairy lord's late-life triumph.
What actually gathered there was closer to a reunion of the losing side of 196 AC. Lord Gormon Peake's iron patience, Black Tom Heddle's steel, Ser Alyn Cockshaw's ambition, and a golden mystery knight calling himself John the Fiddler all converged on the wedding feast, and Ambrose himself — wanting the prestige of hosting a black dragon's return without quite wanting to be caught having wanted it — tried to have the conspiracy both ways, which is rarely a posture history rewards.
It did not reward him. When the plot collapsed before dawn, the crown's answer to Whitewalls was architectural as much as legal: the seat was attainted and pulled down stone by stone, so thoroughly that travelers on the lakeshore road afterward knew the site only as a scatter of pale rubble the local smallfolk quarried for barns — a house that built itself a monument and got a demolition instead.
The page and the screen
No season of the show has been announced for The Mystery Knight, and Whitewalls, the Frey wedding, and the conspiracy it conceals remain entirely unadapted; everything known of Lord Butterwell's fall currently exists only on the page.