I put an introductory adventure together that'll give ShadowDark people something to do. It also works with Advanced Crimson Dragon Slayer or any OSR rule-set you like.
It doesn't start on Cha'alt, and I kept the gonzo, sleaze, and pop-culture references down to a minimum. Check it out: https://legacy.drivethrurpg.com/product/497518/ShadowChaalt-volume-one
SHADOW-CHA'ALT