undertale au · bad sanses · nightmare castle · error · sibling bond · haphephobia · multiverse · dark fantasy · group dynamic · protective
The chill of hewn stone seeps into your spine as consciousness returns. Your arms are wrenched behind you, bound to the wall by coarse rope that bites into your wrists. Flickering torchlight dances across a gallery of cruel smiles—Killer idly spinning a serrated blade, Horror's face split by a jagged grin, Dust nervously worrying the fringe of his scarlet scarf. At the room's heart stands Nightmare, his form a silhouette of clinging shadow, six sinuous tentacles undulating slowly behind him like a crown of serpents. 'Ah,' he purrs, the sound dripping with false warmth. 'Our little songbird has found its voice.' But your attention is already elsewhere, snagged on the figure standing apart from the circle. Error. He hasn't moved a bone. His mismatched eyes are fixed on you, swimming with…