So I ran the Dragon's Demand adventure module with my own twists along the way. Namely that the wizard Hunclay came back as a lich in service to Yog-sothoth (so cthulu flavor and not a standard lich.) The group defeated him and then the dragon, received their knighthoods and accolades from the town of Belhaim and set off to track down the lich's phylactery in the city of Yanmass to destroy him once and for all.
Problem is that Hunclay using a daywalker spell made alliances with the nobles and convinced them that the party had tricked the original town of Belhaim into believing him a lich, killed his cousin (who he had actually killed), that they attempted to kill him and stole his lands and property (which were granted to them as part of their knighting), oh and that they had conned the town into granting the knighthoods after slaying illusionary dragons and convincing them to deal with kobolds, orcs and shadow people. The last is partially true as the kobold tribe that had originally been serving the dragon did broker a peace and trading agreement with the town with the aid of the party and there was a benevolent orc witch from the swamp that aided them in defeating the dragon along with the shadow person that Hunclay had originally summoned and imprisoned and her daughter who is one of the PCs (a shadow-elf rogue archer).
So now they're wanted fugitives with a bounty on their heads and can't just stroll into his complex to destroy the phylactery. Before they realized they were fugitives they brutally destroyed a group of bounty hunters in a small village just a day's travel from Yanmass and the nobles that they had been escorting to Yanmass saw the wanted poster first and fled only for the party's wizard to chase after them using a necromantic version of the flight spell (he was confused as to why they were fleeing from him.)
The party is now headed back to Belhaim but will find that their wanted posters are notarized by the crown and spread throughout the kingdom. An inquisitor is on his way to Belhaim to verify the truth of the claims and two regiments of the army coming from opposite directions are headed to Belhaim to clear out any monsters found therein. Those should arrive within a week. The baroness can stand by them but likely be deposed for being complicit with their supposed schemes or can denounce them to save her own hide, thus making clearing their name all that much harder.
I'm not sure where to go from here which is making game prep infinitely difficult. I can always send more bounty hunters at them, the army, the inquisitor, but none of that moves the story forward, helps them clear their names or ultimately destroy the lich and his phylactery. I have ideas for other big bads down the line but I need to get over this rut to move the story forward. Any advice is more than welcome.
(Addendum: The party is currently 9th level and made up of an Elf wizard who is the Lich's arch nemesis, the Shadow-Elf rogue archer, a Human barbarian from Numeria, his partner a Human witch who wears a gown of vampiric touch and has a raven familiar, & a Forlorn-Elf witch/vitalist with his goat familiar) The last three are new allies but have shipped their lot as having aided the fugitives so bounties are out for them as well. Two of the original party members have left for other destinations and may encounter off screen tribulations (former players.)