Anyway I'm finding my approach is essentially making a puzzle, and then needing to find a way to unravel it. I need to know when the antagonists are moving and in what ways it would be visible, and then find ways for the players to discover clues to this deeper conspiracy. Where should I put leads? How would following those leads be resolved? What would be the consequences of false leads? How would I get the player party back on track when they've deviated too far from where I want them to be?

I'm posting not only to share thoughts with fellow GMs, but to ask if anyone else has plotted very deep, rich campaign stories and if anyone has any tips.

I am finding that rather deal with the "player's" motivations and goals, I almost entirely deal with the NPC's motivations and goals and go from there. For example, Mr. Boyd is looking to move his way up in the criminal organization and wants a series of events to take place. He needs some talented pawns to make this happen. That's where the players come in. In this group, the players received a ship for payment, however, there is cargo aboard that must be delivered as part of the deal. Unwittingly, there are now being used by the criminal organization. They don't have much of an option to stray. You just don't start working for the Black Sun (even if ignorant of that fact) and leave! Right now, there are caught up in a struggle between a younger, ambitious criminal and an older, established, more-powerful criminal who always beats the younger one down to let him know it.

The antagonists make moves when they need to. What time frame are THEIR plans on? I think that things happen regardless of what the players do. Leads? I like to bury a lead in a bungling henchman's actions. Sounds like the leads are linear....find clue, follow it, resolve it. I like to think that clues build up and then the npc's reach a point where they must make a decision. I have the two aforementioned criminals and the npc's will get offers to work for each of them against the other one. Actually, I have no idea where it will go, and that's okay! Not everything needs to have a conclusion in-mind. Yes, eventually, I want them to get caught up in actions against the Empire and maybe even assist or join the Rebels. But right now, not everything needs to lead in that direction. They're really enjoying the current adventure and each of the major criminals have a companion woman: one a seductress and one a Grace Jones 'May Day' npc.

I am also finding that the rolls of the dice are changing plotlines. I had one player roll 7 successes on Leadership roll to calm down an argument between two groups of npcs. It made him quite a respected man instead of some goon mercenary.

As far as leads go, the group found a Datapad on a bounty hunter (from someone else's one=shot adventure). PLENTY of stuff on there! Contacts for weapons, illicit materials, a street doctor, and a few bounty contracts. I also find that putting in humorous and antagonistic npc's helps take the seriousness out of it all and allows true plotlines seeds to be sown without notice (i.e. not every npc they meet is a plot hook). Sometimes there's just a jerk at the bar who relentlessly insults someone in the group. No plot going on, but it's fun.

Hope some of this helps.