The changes I made:
- every PC was already a faction member
- the factions had already had some sort of Big Talk Meeting and decided to send out some mixed groups to investigate the cult's activities
- the PCs were in an inn when the cult attacked Greenest
- I didn't make stealth checks during the village-traversal; I just checked for encounters using a procedure I'll describe in a later post
- I used my own encounter tables
It was miserable, but I mean that in a good way. I was expecting a TPK nearly every second, but everyone managed to escape without a PC fatality.
They ended up running into two encounters on the way to the keep. All the way, they were escorting villagers.
It was pretty dark.
By the time they saved some children and an old man at the gates and made their way through, the beefy PCs were each at 1 hp, and the wizard was at 4, all resources spent.
They watched the gates close and people get slaughtered against them.
It was unpleasant.
As they took a breather, I introduced the authority figures, who asked (but did not require or expect) them to head out the secret entrance and try to do what good they can in the village.
The wizard's player #NOPEd out of that and decided to use an alternate PC for this part. Wise choice.
The castellan's wife is the priestess at the temple; maybe you could go there? The party agrees. Rat swarms in the way are scared off with torches.
They take the river to the back of the temple, intervene to mitigate some war-horrors, and engage the besiegers of the temple, which are far more numerous than they thought. They could have waited or scouted to see the numbers involved but didn't.
Although they ganked the group in the rear, the B group had 10 kobolds, 3 cultists, and 2 drakes, which, for 3 level 1 PCs, ain't something to sneeze at.
Despite that, they cut a fighting retreat back to the keep, save a ton of villagers, and are big heroes two game-time hours into their career.
Maybe they'll live through the night.