B1 In Search of the UnKnown By Mike Carr, The King in Yellow, & The Thirteen Parsecs rpg by Jason Vey.

 "Many years ago, rumor has it, two noted interstellar personages in the area, Rogahn the Fearless (a fighter of renown) and Zelligar the Unknown (a magic-user of mystery and power) pooled their resources and expertise to construct a home and stronghold for the two of them to use as a spaced base of operations."

 What if the TSR classic era module B1 In Search of The Unknown by Mike Carr was used with Jason Vey's 13 Parsecs rpg?! 
Rogahn the Fearless (a fighter of renown) and Zelligar the Unknown (a magic-user of mystery and power) were a part of the interstellar scene where they were fighing the rising tide of the Yellow Mythos.
These two powerful influences constructed a hidden complex known as the Caverns of Quasqueton. And they disappeared. 
Thier legends drifted into oblivion until the first humanoid raiders and servants of the King in Yellow appeared. Orcs foul things mutated by the King's influence & insane begin to lay waste to the intersteller frontier. Perhaps the answers to thier spreading insanity can be found in the Caverns of Quasqueton?! Even as the King in Yellow's influence spreads perhaps all hope is not lost?! Now the question become have  the Caverns of Quasqueton come under the corrupting influence of the King in Yellow?! 

Now I didn't make any of the King in Yellow influence up. That would be Jason Vey whose used the Chambers mythos as a jump of point for the Thirteen Parsecs rpg as one of the possible campaign settings. Within this setting there are multiple tendrils of the King in Yellow infiltratrating intersetllar society on a number of levels. 
There's more goingg on here though. The King's influence is having a corrupting influence on interstellar affairs. This has put everything on edge and it seems to be getting worse according to the campaign setting. 
Thirteen Parsecs is easily understandable as a role playing game if the players and DM's are familiar with the world's most popular role playing game. The Science Fictional Rpg elements add something a bit different to the Robert W.Chambers King in Yellow mythology. Couple this with the background of Thirteen Parsecs and things should get very insane and interesting.