Sometime soon, I am going to start a game for some close friends, some of whom have traveled thousands of miles to be available to play (okay, there might be a job involved as well, but i assume having me run a game was the important consideration 😀 ).
Characters begin at third level, set on Golarion, done with innate bonuses replacing most magic items (and some other rules changes, both Unchained an not).
Background
One night, weeks or months ago, you stopped sleeping. For weeks, you simply laid awake for the entire night. You found resting for hours every night allowed you to avoid exhaustion, but true sleep eluded you. Wise women, hedge wizards, shamans and alchemists were all stumped, unable to provide a cure or cause (though for a few gold, all were willing to keep suggesting theories). Nothing helped. You have not slept since.
One night a few weeks after this began, as you took a walk while most others were asleep, the blue mist came. A heavy fog, so thick you could see no more than 20-30 feet. Your surroundings faded, to be replaced by dark shapes with glowing green eyes, chittering sounds, sudden warm breezes that came from damp, cold air, and weak tortured screams from far away. A towering religious-looking building loomed in the distance, its form visible through the mist.
You felt a sharp pain in your back, felt fetid breath on your neck, and found yourself standing not far from where you were walking, the last traces of blue mist fading.
No one else saw the mist. In the days to come, when the mists returned every 3 to 5 days, no one ever noticed even if they watched you all night. But you faced the misty nightmare realm more and more often, sometimes attacked by tall, thin men with gaunt faces and strange hooked blades, sometimes caught in a sticky web that burned your skin, and sometimes wandering through the moans of damned you never saw through the thick blue haze. The events were hard to recall with clarity, as through from a fevered dream, but they seemed to get worse, and a sense of slow dread built for you each time the blue mist came.
The one thing you did keep seeing was the enormous church or shrine, an ornate structure surrounded by a bottomless pit and accessed only by three bridges (with a forth broken bridge sometimes visible, sometimes not).
Local folks began to fear you were cursed, or perhaps doomed (or perhaps chosen by destiny, based on how supportive the people your background are). Inquiries into the nature of the mist, the phenomenon of sleeplessness, the gaunt men, all proved fruitless. But through research (or your own knowledge, or a chance encounter with a traveler), you discovered the shrine matches the description of the Starstone Cathedral, in the center of the legendary city of Absalom.
If you are to find answers, it’ll be there.
Characters may be from any nation on Golarion, but all will have come to Absalom to investigate the Starstone Cathedral. If you are native to Absalom, the sleeplessness is recent, and the Cathedral visible just recently. If you have traveled from Tian Xia the mist has come to you for months, and you are just now ending your long journey to Absalom (and have learned Common along the way).
Now, it is time to seek the source of the Nightmares of Absalom!

Everyone receives three traits. One is the campaign trait Sleepless in Absalom, The other two may be selected from normal sources.

Sleepless in Absalom. You are immune to magic sleep effects. You must rest for eight hours every night, but are not asleep (and do not take penalties to Perception checks made while resting).