The following all happens in a town and the nearby surrounding area.
So my party, hereby referred to as their classes are currently third level and have infiltrated a cults hideout, they went there looking for Rogues friend and snuck in with disguises and managed to bluff their way into where the friend was being held. She was in a holding cell. After some deliberation they devised a plan to cast silent image and sneak her out, they couldn’t manage to pick the lock and Cleric smashed the door in, this was heard by nearby cultists and they decided to just make a break for it. The cult massively outnumbered them and the party got surrounded. Sorcerer, who is an Aasimar and can fly at 3rd level, flew past everyone and escaped while the rest of the party surrendered. We ended the session there and Sorcerer told me after the session that they plan to go to Cleric’s tavern to get the barkeep and any tough looking patrons to form a quick mob.
The conundrum here is that I can’t think of a good reason for these cultists to not just kill the party aside from that’s not fun. The cult is aware that one of them escaped is probably going to bring the law down on them, so they’ll also want to leave. If I was them (and in a way I am) I’d probably kill the witnesses and bail.
Any advice?
A stereotypical high drama continuation could be:
The cult know the law is on it’s way, and must now accelerate their plans for the final ritual to summon the dark lord to protect them and show the world the Might That Will Usher In the New Era.
Fortunately, the hapless adventurers could be just the sacrifice needed to boost the final steps.
If you need to kill time, the ritual might be preceded by a set of cage fights to find the most worthy sacrifice. Or an elaborate set of trials. Or they’re stripped of equipment and/or drained of magic before having to fight themselves out of the situation long enough for the cavalry to get there.
Bonus out is both the summoned Big Bad as a boss fight, or if they derail, they might find themselves fighting the High Priest and their most enthusiastic lieutenant/followers while they perform a ritual that adds puzzle like elements to the fight (the boss priest has a shield as long as the followers live, or elemental pillars that have to be destroyed before damaging the priest, etc).
Of course the cavalry arrives just in time, and the mob of townsfolk spread out to fight the cultists, so that only a few arrive to aid at the boss fight.
Or you could have a cool siege type episode.
The cult can’t kill the adventurers yet, because they have to prepare the compound for the onslaught of the law and mob. They need to prepare arrows and reagents for the palisades/walls, prepare wards/rituals/cauldrons of hot water, organise the defensive teams, and the High priest needs their guards to protect the ritual of the demolition wave that will wipe out the assailants/everything outside the ritual circle for a mile wide radius after a long ritual that in it’s haste is leaking dangerous magics making a fight in the ritual room that much more hazardous.
The captured adventurers of course escape their improvised cages/fetters in time to sabotage and/or infiltrate the defences and let the law and mob in. And fight their way to the inner chamber just as the ritual is nearing it’s climax.
Bonus cinematic points if the ritual chamber is marked by a pillar of darkness, swirling clouds centered on it, or similar so that the outside sorcerer knows where to go.