A while back my Star Wars group (in a now ended campaign) awakened a 4000 year old Sith Priest on Yavin 4 and inadvertently led him to the Temple of Exar Kun where he made contact with the spirit of his Master/God and the small Cult in the Temple. They left before it hit the fan, but they know a Inquisitor group sent to investigate the spike in the Force at the contact was mind controlled by the Priest. They were never bothered about follow up and went on to acquire a shipping route contract and a decent (mostly) legit income. Just as the campaign was ending however, after being unable to raise a contact on Yavin and hearing stories of odd disappearances they decided they should do something about the mess they made, but player/gm fatigue was quite large by then and we stopped.

My players however have expressed in picking this back up, but rather than use their 1500 point high end characters I have been musing doing low level characters who are working for their high level one's Company doing missions which have an aim to impact the final fight vs the Priest and Cult. I was thinking of doing this on a timer- the Cult is attempting to resurrect Exar Kun at X point and they have until then to work against them. I was thinking missions like:

-Recruit more forces for the fight: the players like more diplomatic missions so gaining recruits might be there sort of thing.

-Gain more ships: just before the end the High-Levels got word of a Venator that might be salvageable, so sending the new crew to get it is an idea

-Stop the Cult gaining X or Y McGuffin

-Scouting on Yavin IV

-Preparing for the Big Fight

Trouble I am having is how to time this - do I set a fixed number of missions? Do I pick a date on the calendar and just keep notes of the days until the resurrection ritual but drop hints its coming to chivvy them along?

Also what if they fail a mission or succeed exceptionally well? Do should I record impact for or against the Company and Cult?

Any GM advise welcome!

NOTE: Vader and the Empire are unable to just sweep in and glass Yavin as apart from the first 'burst' the Force has gone quiet, and the Controlled Inquisitors reported everything was fine, and there is a Major Insurrection broken out on Corellia, and they are gearing up for Hoth...

Real timers are almost always doomed to failure in any RPG. There are just too many variables and whatever timer you set, the players will be either early or late, often comically so. Most published adventures I’ve seen with a “timer” always have the players arrive at the critical moment, no matter how long they actually take. I’d advise doing the same and have the outcomes of the various missions provide benefits/penalties based on how the players did. This way the players arrive just in time to stop the cult (even if they wasted a year looting bodies or whatever), but the outcome of their missions dictate how hard or easy it will be to stop the cult. Naturally, you don’t tell them this and you keep pressure on them - the cult is making progress, oh no! Have the cult’s progress be tied to the players. The PCs complete mission #1 and the cult makes some progress. Rinse and repeat. Regardless of actual time, the PCs will arrive just as the cult is about to complete the ritual. Bonus: those prior missions will have real consequences.

If you want timers, they need to be completely transparent to PCs to be effective and not just 'suddenly you're screwed' buttons. One example I used was this for the PCs attempting to stabilise a sinking Lucrehulk on Bespin: https://imgur.com/a/trvKMp4

The effects of their actions and the world had transparent effects on the tracks (e.g. O2 decreases each round until they fix the hull, doesn't go up until they fix the atmospheric generators). But O2 could also suddenly drop if they ended up breaching a wall in a fight- but they had a clear idea of what would happen, what the levers were, and when things were likely to start having an effect (e.g. when you hit a colour change).

So for this I'd probably have a 'We suspect it'll take them around X months to finish the ritual' tracker. Then PCs can think about trying to sabotage them to push back the timer, and maybe have some other clear trackers for 'Cult resources', 'Company fleet', that kind of thing.

Thank for the thoughts there.

I have been trying to track down any existing campign with the same sort of 'timer' idea, but not had much luck. Any suggestions please?

The best example I have is from Pathfinder, specifically the Legacy of Fire adventure path. The short version of the story is an efreeti (fire djinni) is going to use 1000 stolen wishes to turn himself into some massive fire beast to impress a fire goddess he has a crush on. Throughout the adventure, the PCs find out he’s been stealing and using more wishes and getting closer to his goal which will destroy the world. Spoiler: he never uses the last wish (unless the PCs fail to kill him and are killed themselves, a.k.a. they fail). In fact, the adventure has him preparing to use the last wish as they enter his room to kill him, whenever that might be. All along the way, the PCs learn more about his plan and the effect all these stolen wishes is having, which is bad. The tension and build up is great. With each success, the PCs learn the BBEG has used another wish. Hopefully, that paints a good picture.