Exo III

Exo III is a formerly-inhabited planet, the homeworld of people known as the extinct "Old Ones."

At the time of measurements, the planet's atmosphere was within safety limits by Federation standards.

Its gravity was 1.1 of Earth's, to which it also used to bear a remarkable resemblance before its sun began to dim at least 500,000 years ago.

As the star of the Exo system began to gradually dim, the average surface temperature on Exo III gradually fell to one -100 C over the course of 500,000 years.

The "Old Ones," a humanoid species who lived on the planet, fled the surface in favor of the dark underground caverns, in order to escape the increasingly inhospitable surface.

Exchanging their open and free society for an increasingly mechanistic one, the "Old Ones" constructed more and more advanced android servants. They began to program the androids with a sense of pride in their abilities, and a desire to survive as well. At some point, the "Old Ones" became fearful of these androids, and began deactivating them. With their survival threatened, the sentient androids exceeded their programming, and fought back against the "Old Ones," killing them in what they considered self-defense. Soon their fight was over, causing the extinction of the "Old Ones."

All of this was uncovered in 2261, when Professor and scientist Roger Korby led an archaeological expedition on the planet.

While visiting the planet, Korby encountered one of the androids, who was still performing maintenance on the machines once used by the "Old Ones."
Suffering from extreme exposure, Korby struck up a conversation with this android, discovering the existence of a still-functioning android duplicator, and created an android duplicate of himself.

When communications with Roger Korby were lost, two further expeditions were sent to Exo III in an effort to locate the expedition, but both failed to find them.

Five years later, the Enterprise was sent to find the Korby team. Android duplicates contacted the ship, and tried to convince the Captain that android duplicates should be made of everyone in the Federation.
Unconvinced, the crew pointed out that the androids had no sense of remorse, or any ability to experience genuine emotions.

Unfortunately for everyone involved, all of the Exo III androids were destroyed in various conflicts that developed during Enterprise's mission.