When I've got a stubborn idea like that, I like to go to the Big List of RPG Plots and pick one or two and make them work. It's really great. Just reading a couple of them with some ideas in your head gives you a lot of room to make it work on an adventuring level, without giving you anything that might spoil that creativity burning away in the back of your brain.
Just as a quick example, I'll pick two at random: Blackmail and Delver's Delight.
Just off the top of my head, you could have an adventure where the PCs are blackmailed into exploring something dangerous for the guy. Maybe the Lord Governor of a planet will grant them clemency if they recover a holy icon from a neighboring planet, deep in the underbelly of a hive-world where dangerous theives have secreted it. Maybe it's the other way around, and they were exploring a barren planet and uncover something that was never meant to be found, or disturb something that shouldn't have been disturbed, and they're discovered red-handed. Now the law is using them for their own ends (since they recognize talent when they see it, even if it is criminal), and the PCs have got to figure out how to get out from under their thumbs.
You could go deeper- with the first example, maybe they find out halfway through the mission that they're not the only ones seeking this thing, and they uncover a conspiracy where all of them have been gathered up on trumped-up charges and there's multiple teams of seekers, all kept separate and watched very closely, but there can only be success for one group- meaning that they're both recovering their lost posessions and eliminating several troublemakers in the process. Or maybe it turns out that the thieves aren't the bad guys after all- the object belongs to them and the PCs are left with an unsavory choice- either they steal the artifact from its rightful owners and bring it back to their blackmailers, or they help the good guys and now they're wanted by the Lord Governor and are being pursued by a man who commands an entire planet's worth of overt and subtle force?
Before I go way too far, this is exactly why I like the site. It's a great creative aide, and if you're ever caught in a bit of a rut or find yourself re-writing the same adventure three times, it's just the thing to break you out of the habit.