All attempts to communicate with the planet fail. No landing coordinates are given. Power sources and machinery appear to be functional and are actively showing on sensors, but no lifeforms can be detected. Plague? War? Aliens? Astronomical/Geological event? Where did the population go?
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It's a privately owned moon/planet, whose lone resident hermit has passed away. To whom do his assets now belong? Is there a last will & testiment in his palatial mansion that can be "forged"? Why did he die? What were the players supposed to deliver to the planet when they find him? Will they be framed for murder?
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A secret waystation/lair has been discovered. What is it's purpose? To whom does it belong? When will they return?