Clytemnestra Colony

Clytemnestra is a supercytherean planet located in rim space. "Supercytherean" means it's Venus-like and somewhat larger than Earth. Like all Venus-type planets, this one too is an acidic pressure-cooker: dry, dim and unbearably hot, with an atmosphere dense enough to smash interplanetary probes into aluminum cans, all wreathed in an eerie veil of pale yellow clouds, composed of pure sulfuric acid. Beneath the clouds, an unforgiving chaos terrain of dark basaltic rock is concealed.

That's how it used to look, at least.

Planets by Perigee, a subsidiary of the illustrious megascale engineering megacorp known as the Perigee Corporation, has been hard at work terraforming Clytemnestra for the past three hundred years. Terraforming Venus-types is hard, slow, thankless work even by the standards of planetary engineering, generally considered to not worth the hassle compared to simply establishing cloud-city type colonies, but Perigee has a reputation for extravagant gigaprojects. Atmosphere extraction, temperature reduction, reversing the runaway greenhouse effect - the most talented planetary engineers of eight generations have worked tirelessly to turn this desolate world into an Earthlike paradise. Clytemnestra is the crown jewel of Perigee's terraforming business, a proof of the Corporation's groundbreaking and high-quality craftsmanship that can tame even the most hostile planets.

Also, it is failing.