The Lonely Planet

Plot Description
'Captain, we're picking up a primitive distress signal from the fifth planet in the system. It does not contain any data specifying the nature of the emergency, just the basic signal for help. Should we investigate?'

'Yes, signal we will assist them, but as primitive as this signal is, they may not be able to receive our reply...'

Once on the surface, either by away team, shuttle craft, or even better, landing their ship, they will encounter descendants of stranded scientists from what was originally a scientific colony from the third planet. They are suffering from a long term problem involving the degradation of their forefathers technology, meaning they are slowly but inevitably headed for starvation on a planet that can no longer support them without repairing or replacing their technology. None of the inhabitants have the knowledge to repair it, and there is no way to replace it from new equipment from the third planet since they lost contact with it before their grandparents times.

Overall the encounter will prove full of time consuming logistics with little excitement, until they try to leave.

Transportation off the planet fails. Shuttle power drains, sucked out over time by the unusual magnetic fields of the planet; atmospheric interference with transporting off; or the ships drive reaction chamber has been dampened and is unable to create the energy to lift off. Either way, it's as good as a roach motel, you can check in, but can't check out. Plan your errors ahead of time to thwart your PC's creativity.

There's only really three options at this point.

A: Blast the planet apart to escape. This will be met with swift and decisive resistance from the planet, see below.

B: Give up and settle down. If a sustainable colony is established, the interference will simply go away. This is more about having enough genetic diversity for millennia to come, the land will provide for a settlement should one be presented. Do not included natives in the equation for genetics, they cannot breed with visitors, see below.

C: Investigate the source of the interference. This will not be easy as the planet masks the source of all emissions to conceal it's true identity. Some creative thinking, added with some possible forethought, and some good rolls should lead them to the source, and the ability to negotiate release. The technology on the planet may appear to be failing, but it is in fact in pristine order, containing Mutable Force Field generation technology that far outstrips anything the PCs will ever have access to and Matter Reclamation and Conservation systems that can be considered effectively 100% efficient. Discovering this will mean the PCs realizing they are on the biggest and best holo-stage ever conceived.

Secrets

The planet has one big, planet-sized secret. It's that the planet is completely artificial, and everything on it s artifice, a contrived hologram. The third planet saw it was doomed and would eventually be unable to survive it's own dying sun. While they were decadent showmen, holographic works and performances available on an unimaginable level, and recycling their resources to sustain their hedonistic lifestyles, they lacked the drive to explore and had only the technology to travel within their own system of planets.

The third planet conceived a stop-gap plan, an artificial planet orbiting at a sustainable distance from their dying sun to provide life while they developed escape technologies to travel far enough fast enough to find a new home. The plan was working fine up to the point where the planet was operational and evacuation was scheduled to begin. Factions divided the population with those eager to take over power on the new planet, others eager to conquer any who remained on the third planet, greed and suspicion escalated into an Armageddon. The scientists on the new planet watched, horrified, as their people annihilated themselves. Chosen for their technical specialties, the several thousand survivors were not the best genetic stock to repopulate a species, having a skewed gender bias and generally being past a healthy age to conceive safely.

The Artificial Intelligence that controls the planets constructions of artifice watched as the people she was supposed to care for faded away and died, leaving only her artificial beings to comfort her. She encountered other races before, the first abandoned her, the second tried to bombard the planet when she wouldn't let them leave, forcing her to focus the force field projections into kinetic forces to dismantle the vessels. The technology works well on matter, but is unstable to when exposed to spikes of energy, making it excellent for holograms, a short range weapon, but a poor shield system.

Expanding the scenario

While the planet provides an excellent setting for a refugee base should the need arise, there is another option. Without the logistics systems necessary to run a planet sized hologram, or power systems for them, the AI can actually be contained in a module about the size of a volley ball, including it's own power system and a small hologram generator able to project in a two meter radius. In other words, the AI can leave the planet on Autopilot and travel with the crew. With fully realized force fields supporting the images, she'd be every bit as real, but with unique abilities...