Location from The Locked Tomb by Tamsyn Muir
The driest, darkest, most miserable planet in the Emperor's system — a tomb world of bone magic and death worship where Gideon Nav spent eighteen years wanting to leave and Harrow spent eighteen years believing she didn't deserve to.
The Ninth House is what happens when you give a death cult an entire planet and ten thousand years of declining population. The air tastes like dust and incense. The corridors echo. Every surface is carved bone or grey stone. The remaining residents — fewer than two hundred — maintain religious observances for a tomb they are forbidden to open, tended by skeleton servants animated by the House's necromancers. It is the least desirable posting in the Nine Houses by a significant margin. Gideon tried to leave seventeen times. The Ninth House's specialty is bone magic — the animation and manipulation of skeletal constructs — and its aesthetic is unrelenting gothic misery. For Harrow, it is home, burden, and penance all at once. For Gideon, it was a prison she burned to escape.
A dying planet orbiting at the system's edge, perpetually dark and cold. The surface is rock, dust, and the occasional skeletal remain of whatever lived here before the Ninth House made it their personal mausoleum. The primary settlement is Castle Drearburh — a fortress carved into stone, lit by perpetual candlelight, and populated by a dwindling handful of aging nuns and priests who worship the Locked Tomb.
Also known as: The Ninth, Drearburh, The Tomb World