In my homebrew (PF + 3.5 material selected for flavor), the story will soon take my players to the outer planes, but I've hit a snag. The group is on track to be significantly underleveled for the subsequent portions of the planned story. Therefore I'd like to expand the planar jaunting portion of the story to allow them to advance from ~10-13 and I thought it would be fun to incorporate the thoughts of this community, since my present ideas amount to not nearly enough xp. If so inclined, feel free to toss out ideas (general or specific) that suit the encapsulated scenarios below. Sweat the mechanics if you want, or just share your creative juices.
Synopsis: Players travel to 3 locations in the outer planes to destroy minor relics. Players do not possess the means or any developed motivation to go to other planar sites.
Site 1 - Provenance Rim
There is a place on the rim where the grand gears of Mechanus intrude upon stark Acheron, where sound and fury descend upon the most aged cogs and calve off the splinters that will become new battlefields for restless petitioners. This is the Provenance Rim. A delicate frontier akin to a failing clock, it slips through missing teeth and shudders with each imperfect meshing, while the movements pulp the least wary of the territorial generals and lubricate the gears in blood. All of these common dangers pale beside the lodestone that has
ruinously tumbled for eons through the gears and the scabrous cloud of debris that orbits it.
(The lodestone is what the party seeks, but it does not wish to be tamed and will use the confluence of the planes in its own defense. Reaching it under ideal circumstances would require navigating a maze of flying debris where up and down change in seconds. Reaching it while battle rages and siege weapons fly through the debris is tantamount to suicide; rather like climbing through razorwire during an earthquake. The party will almost certainly have to split up, sending their most agile members into the debris cloud while the remainder divert or suppress the violence between formians and the denizens of Acheron.)
Site 2 - Perythion
Undulating swells of shifting sand wash through the boulevards of this forgotten Carcerian necropolis. The pitiful condemned souls of the prison plane scrabble to maintain perches among the toppled buildings that bob and roll like so much flotsam. The heave and pitch offer fleeting glimpses of unseemly vermin, their dim luminescence just strong enough to hint at furtive and deliberate movements in the middle distance. Of what lies beyond there is no sign save for the wet and unwholesome beating of leathery wings, a sound which offers no better bearing than the starless void of night.
(Local folklore holds that a key to escaping the prison plane lies in the gullet of a titanic centipede that prowls these sands and it is the mostly futile hunt for that mythic monster that has brought gangs of petitioners and gaolers alike. The party must gather tidbits of the local lore in order to track down the creature, avoid alerting the prisoners to their aims, and find a way into the beast's craw to destroy that which they came for.)
Site 3 - Lagouro
Where the Pridelands of Krigala skirt the glades of Arborea, there lies a lake forever gleaming with the golden hues of the setting sun. The bacchanal that plays out along its shores is an intoxicating celebration of urge and passion that tempts even the devoutly moral. But there is a subtle wrongness within, a slowly emerging sense that the drama being played out is not the actors' own, but the sordid and sometimes visceral memory of another played out in puppets of the flesh.
(In essence the lake is haunted by a zeitgeist, the accumulated unrealized passions of an ancient fey court that frequented the site. The object the players seek has been hidden within the lake, concealed only by the distractions of the bacchanal and the reflection upon the water. Retrieving it will probably require assuaging the fey in some way, perhaps by taking up a role in their drama or by offering up a loved one as a hostage.)