A short urban-site adventure for APL 13 PCs, and the players enjoy playing a role and being bravados? Maybe custom build your own?
Overview: war can often be avoided by the simplest act of peace. The city the PCs are returning to is to be the site of such an act. Their local grand opera house is hosting dignitaries from a rival nation, there to enjoy a night's festivities with civility in order to seal a treaty of non-aggression. There's only one problem:
The Bardess, Madame Hylene VonKroft, is a vampire.
This creature of the night is the premiere star treading the boards and has been for over a century. Using her preternatural guile and skill, Madame Hylene has reinvented herself several times. She is a powerful spell caster as well. However her unnaturally long life has put her on the list of a powerful outsider, a Marut Inevitable known only as the Thunder in Yellow.
Plot: being famous heroes the PCs are asked to be in attendance at the performance. Minutes before showtime, the Bardess reveals the truth of her "number one fan;" she's known for a time that she's been marked by the marut and certain signs and portents lead her to believe the creature will strike tonight. Madame Hylene begs the PCs to dispatch the Inevitable for her so that the treaty of peace will not be undone.
The Bardess will employ a Polymorph spell as her performance tonight requires her to appear as a Fey Queen on stage. Once so disguised, a Simulacrum of her will be used as a decoy. This should lead the marut away from the opera house to a nearby open air plaza. The PCs will have to follow at a distance undetected until the creature appears, then deal with it.
This is a 5 Room Dungeon type scenario:
1. Entrance/CR 12: the Bardess hires a rival adventurer group, foul mercenaries of ill repute, to call out the heroes. These 5 adventurers pick a fight with the party but are under strict orders not to slay them. The fight ensues and should end with the defeat of the bad guys and their revelation of who they work for and that she'd like to meet them. If for whatever reason the rivals are all slain, their employer should be noted among their belongings, by their fleeing souls through Speak With Dead, etc.
2. Trick or Trap/CR 13: the PCs, following the information they gained from their rivals, the PCs are entreated to the dressing room of the famous Madame Hylene. An ominous storm begins overhead, seemingly from nowhere. As the rain begins to fall, the party arrives to have a Social Encounter with the Bardess. The hope is that she convinces the PCs to guard her simulacrum but she may have to employ trickery, deceit, blackmail or other unsavory methods to get them where they need to be.
3. Setback/CR 14: following the direction of Madame Hylene the party is back outside, heading for the plaza. The storm has mysteriously gone from bad to worse (apply environmental penalties on mundane Perception checks, ranged attacks, etc). As the party approaches the sky cracks; in the distance far ahead, near the presence of the simulacrum, a large figure in golden armor appears, each step it takes resulting in a localized thunderclap. In the air directly above the PCs however three four-armed maidens with alabaster skin and twin-hooked weapons stand sentinel. The monsters, x3 Valharut Inevitables, use Dimensional Slide and Air Walk to engage the party and keep them in place for a couple rounds while the Thunder in Yellow smashes the simulacrum to bits.
4. Climax/CR 15: the storm reaches a terrifying crescendo. If you'd like you can have a Call Lightning effect going off targeting PCs or something. Thunder in Yellow, realizing his quarry has tricked it again, will now do battle with the PCs demanding to know where the Bardess is. This is what the party was hired to do and is a straight-up smack down.
5. Revelation: this one's completely up to you as the GM. You can either have the party arrive just in time to witness the performance of a lifetime as Madame Hylene cements a lasting peace between 2 nations or you can have them return to a scene of utter chaos. You see it could be that, while the party took care of the Bardess' little "stalker" problem she was busy assassinating a foreign dignitary and then using yet another Transmutation spell or Disguise magic item or whatever to frame one of the PCs for the crime!
Personally I like the "framed for murder" ending. This can lead to another quick, 5-room dungeon style adventure where the PCs clear their name and re-establish the peace in doing so. Or it might also result in an interesting recurring villain in Madame Hylene VonKroft.
