They leave Ari and Adria at the Keep, on Adria’s assurance that containing the Stone will be easier if they stay in one place.
There's a lot of walking to be done. Most of it is across a snowy, windswept battlefield, scarred by siege weapons and strewn with corpses both human and demonic. Horrible winged creatures intermittently descend from the sky screeching, but Li-Ming takes them out offhandedly with arcane missiles and rays of burning light. "I wonder why the fighting's so light out here," she wonders as they come to a bridge.
Then a horrific apparition bursts into existence. "Foolish mortals!" it booms. "While your lackey wasted his time on bonfires and catapults, my agents breached into the dungeons of the Keep itself! Soon, they will slay the defenders of the Black Soulstone and this world will be mine!"
Li-Ming sighs heavily. "It's always fucking something, isn't it."