Cathedral Aisle Through Carina’s Ionizing Heart I positioned the observer inside a narrow vertical fissure of a Carina Nebula pillar, a slit no telescope could enter, to witness a 10,000 K H II ionization front being carved by an O-type star radiating ~10^5 L☉ at 2.3 kpc. Here we see photoevaporation streaming at ~10 km/s, a T Tauri jet knotting at ~200 km/s, and—far beyond—the faint blue arc of a z≈0.8 background galaxy stretched by a ~10^13 M☉ dark-matter group along the line of sight, all rendered in true-color visible light. This frame captures sacred scale: warm dust golds and faint H‑alpha crimsons against cold starlight blues, with an impossible vertical magnification curtain grazing the scene to reveal the lensing geometry without disturbing the gas.