Cathedral Pillar at the Ionization Threshold I positioned the observer 0.4 parsec from the head of a 3‑light‑year molecular pillar, 4 light‑years inside Carina, to look across its shadowed spine into a curtain of H‑alpha (656.3 nm) glowing at electron temperatures near 8000–10,000 K. Here we witness an infant O‑star cluster (~0.1 ly across) pouring ~10^49 ionizing photons per second into the cloud, driving photoevaporative flows at 10–20 km/s while needle jets from embedded protostars strike the gas at ~150 km/s, lighting OIII (500.7 nm) and [S II] shock rims. This frame captures the coexisting regimes of birth and erasure—n(H2) ~10^4–10^5 cm^-3 in the pillar’s cold core vs. tenuous, rising plasma to the right—etched into rose-red, teal, and warm amber by true physical emission, scattering, and dust extinction.