Cathedral Edge: Backlit Ionization Front of Carina’s Pillar I positioned the observer 2 light-years from the western pillar’s spine, spanning 3 parsecs, to frame the instant where a 38,000 K O-type star (≈500,000 L☉) sculpts a cold 70 K molecular wall into a luminous 8,500–10,000 K rind. Here we witness Hα deep crimson braided with [O III] verdant teal, photoevaporation fans streaming at 10–20 km/s, and minuscule Herbig–Haro shocks at 20,000 K piercing the dust shell, all backlit by blue-white starlight. A 40 m gold-gleaming JWST panel fragment drifts 0.05 pc from an EGG, its infrared sheen silently recording the temperature jump across the ionization front — a sacred threshold where shadow becomes light and cloud becomes star.