The Winding Stair

In the great city of Temetria, in a dank alleyway seldom travelled by more respectable folk, stood an old, yet oddly beautiful doorway, in which was carved a picture of three intricate spiral seashells, in the side of what may have been a warehouse, a brothel, or something else equally as common. It was the first time I had seen it, and I doubt anyone else could, for as I turned the tarnished silver knob and pulled it open, the other inhabitants of the alley seemed to forget I even existed. It was 18 years ago that I entered that strange door… and I haven’t found my way back home since then.
Liam Longnose, Gentleman Thief of Temetria

The Strange Door
In the city of Temetria, and in many large cities in many different worlds, stands an ancient, beautifully carved doorway, most in inconspicuous locations, such as alleyways, warehouses, libraries; even in the basements of palaces and mansions. Not everyone can see these doors, but those who do easily open them with a simple turn of the knob. In some worlds, these doors are known of and well guarded by the local government—in others, they stand in the ruins of once great cities which have long since crumbled to dust. In some worlds, the doors lay ajar, their hinges broken by the creeping vines which have grown up around them over the centuries—in others, adventurers have found keys capable of locking them, preventing otherworldly menaces from invading their fragile realities.

Properties: Each door has a unique pattern on both sides, a symbol or picture which represents its respective world carved into the door’s beautiful wood—and each world contains a key capable of locking the door from the inside (the world’s side, as it were), though it may be lost or hidden somewhere far from the door. This key can not be taken outside of its world. The doors all lead to the same place: the Winding Stair.

Upon passing through the door, I found myself on a large and winding stair. I began to climb, watching as I passed countless doors much like the first, each with a different picture carved into the wood. When I happened upon a landing which opened up into a hallway, I followed it to another set of winding stairs. I then decided to check some of the doors—some were locked, others were jammed shut, and yet some of them opened to strange places I had neither seen nor ever imagined could have existed. As I wandered the stairs, halls and foyers of this strange place, I eventually realized that I had no idea where I had started. Since then I have explored countless worlds, gazed upon hundreds of alien skies and examined thousands upon thousands of doors… yet no matter how hard I search, I have never again found those three spiral seashells.
Liam Longnose, Gentleman Thief of Temetria

The Winding Stair
Through all of these doors lies the Winding Stair. The Stair is a maze of stairways and halls full of countless doors, each leading to a different world. the Stair is effectively infinite, so though there are in all likelihood thousands of travellers in the Stair at a time, the odds of two adventurers stumbling upon each other are very small. The stair is a confusing place, so unless a traveler takes care to map his route, he will be unlikely to ever find his way back (attempts to leave a breadcrumb trail or lay down string will not work—unattended objects on the Stair disappear when left out of eyesight). The Stair does not function as normal world do, it is effectively 'out of time'. This means that travellers do not have to eat or drink while on the stair, and they do not age, though time passes normally on outside worlds. In addition, adventurers may understand any language on the stair, so diplomacy with other, potentially alien intelligences is possible.

Properties: The layout of the stair is apparently random, though it is actually an accurate representation of the proximity of different worlds to each other in the multiverse. Each door has a chance of being locked, broken/jammed, or opening into a city, ruins or the wilderness. Though random wandering will get one helplessly lost very quickly, a carefully documented journey would allow one to chart courses between different worlds and travel between them with little effort.

Hooks
(1) Upon exploring the Stair, the adventurers stumble upon Liam Longnose, Gentleman Thief. He may either: (a) inquire about the whereabouts of a door with three spiral seashells upon it. or (b) explain about the Stair and its nature and his numerous years wandering through it. or (c) as follows…

(2) The adventurers come upon a man (or other sentient creature) curled up in a heap, sobbing to himself and repeating over and over 'must not get lost must not get lost must not get lost…'. Conversations with this man may result in being ignored due to his shattered psyche, or may snap him out of it, after which he asks for help finding a particular door (which the adventurers just happen to have seen not too long ago)

(3) It is said that the gods of countless worlds resides at the top of each stairway. Can the adventurers seek out the help of one of these deities in order to return home?

(4) In a enormous dome, at the end of a strange looking (by the Stairs standards) hallway, the adventurers encounter a wizard in what appears to be a makeshift laboratory. He reveals that he used his magic to carve out this place for himself, and uses it to research the properties of magic and the multiverse (bonus that it effectively makes him immortal, if maybe a little crazy). He knows of the layout of much of the surrounding territory of the Stair and can the adventurers find their home world’s door, but he requires them to accomplish a task for them. He gives them a map leading them days away through the Stair to a world from which the wizard requires a certain rare substance for his research. What strange world will the adventurers be required to traverse?

Notes
***Once into a new world, odds are adventurers will not speak any local language, unless they have magically prepared themselves for this (or there happens to be a common multiversal tongue, who knows).

***This is great for a one shot alternate world adventure. Just have a wizard send the adventurers on a transworld journey, and who knows where they can end up.

***Remember, even though the odds of meeting anyone on the Stair is small, the rules of good storytelling make it actually quite likely. Feel free to throw any and every sentient creature (remember, only sentient creatures can see and open the doors) at your adventurers that you can think of.

***Finally, just because I imagine the Stair to be rather stark and empty, don’t be afraid to have some weird,

Through the Looking Glass

style stuff going on. A random painting (think Escher) hangs on the wall of a certain hall; random voices whisper to our adventurers on a certain stair; the adventurers are accosted by a Great Gazoo-like figure who watches over the stairs… The possibilities are endless! Go nuts!