The violet-red ceiling of the Spire-grid began to lower, the artificial aurora thickening until it felt as though they were traveling through a tunnel of bruised light. The "Last Bastion" finally appeared, not as a castle of stone, but as a colossal, hollowed-out ribcage of a leviathan that had died before the first note of the world was struck.
The bones were made of a substance that sat halfway between iron and bone, pulsing with a faint, rhythmic amber light.
"Zero, perimeter check," Eren ordered.
The construct didn't just chirp; he disassembled. Zero's chassis split, releasing a dozen micro-spiders that fanned out into the grey dust, their sensors weaving a lattice of red light across the entrance of the Bastion. He remained on the wagon's edge, his primary optic spinning like a turbine.
"Master Eren, wait," Zero's binary translated as a sharp, staccato warning in Eren's mind. "The resonance inside... it isn't the Church. It isn't the Master. It's... *mechanical*."
