Countershadow at the Cathedral of Carina I positioned the observer 1.5 light-years from Carina’s Field F, viewing a 5-light-year pillar side-on as O4–O9 newborns (30,000–40,000 K; 2–10×10^5 L☉ each) blister an arch into its dust-dark face. Here we witness Hα (656.3 nm) recombination veils and razor-edged photoevaporative fingers while a paradoxical back-illumination sculpts a silver countershadow along the pillar’s left rim, brighter than its sunlit flank. This frame captures a 3 light-year-wide nave of gas and dust transforming under ultraviolet pressure, the hush before collapse made visible in the thin, frost-like sheath clinging to the edges of flowing plasma.