The Outside

It doesn’t look like much at first glance, if one notices it at all.  Maybe it looks like a pile of tumbled stones, maybe it’s a burned out shell of a building.  People don’t seem to see the same things, or even see them in the same place.  But whatever it looks like, wherever it appears, there’s a vague feeling of uneasiness, or wrongness, like there’s something about the ruin that shouldn’t be.  Most people just hurry past and try not to think about it.

But sometimes, if one knows how to see, or if one is in the wrong place at the right time, they see a little more.  They see something hidden under the ruin, a building of immense size.  They’ll wonder how they never saw it before. 

And if conditions are right, maybe if they have a little… otherworldly help, they can enter the Palace of Infinite Corridors.

The Inside

The Palace of Infinite Corridors is no ordinary ruin, as it’s shifting facade would suggest.  Most would think it the work of some deranged sorcerer or something similar.  If only it were something that harmless.  In reality, it’s nothing less than the home of demons.

This is the place the Court of a Thousand and Nine Sorrows calls their own.

The Palace is not of this world, and follows its own rules.  It’s bigger on the inside than it seems to be on the outside, and the corridors seem to change at random, leading to different places at different times.  There’s no telling how many floors it is.  It’s very, very easy to get lost, and this is not a place mortals are really welcome.

The Palace is effectively endless, changing at the whim of which ever Sorrows happen to be around at the time.  Their powers are greater here than they are in the mortal realm, and they can alter the physical reality of the Palace as they see fit.

All Sorrows instinctively know how to reach this place, and can do so from anywhere, not just from places where it appears to mortals.  Some of them stay here most of the time, while others just stop in periodically, taking a break from their current plans.  The place is big enough that the Sorrows can avoid each other when they’re here, and that’s the way they like it.

There are individual areas of the Palace that many of the Sorrows have claimed as their own; a combination of lair and personal space.  Each has been formed and "decorated" by the Sorrow that claimed it to suit their individual natures.  Depending on the Sorrow in question, some areas are more threatening than others.

There is also a large central Hall.  This is the one constant of the Palace of Infinite Corridors.  No matter how they change, the endless corridors all meet at the Hall, assuming one makes it that far.  The Hall would make an ideal meeting space, if the Sorrows were organized enough for such things, or recieving area, if the Sorrows didn’t largely object to guests.  Mostly, it’s treated as neutral ground.

Emotions have a strong tie to the Sorrows, and as such, to their home.  People’s emotions tend to have an effect on where the corridors take them.  If they are angry, they’ll stray ever closer to the Sorrow of Anger’s domain, for example.  The only way to avoid being essentially herded by the Palace in a particular direction is for the mortal to maintain tight control on their emotions.

Entrances

There are certain places where the Palace of Infinite Corridors touch the mortal realm.  These are the only places mortals can enter it unassisted, although it would take some doing.  These places appear as a ruin of some sort, and the bleedover from the Sorrows’ presence gives these ruins a disturbing, "haunted" atmosphere.  The ruins can appear anywhere, anytime.  Some think that there’s only one real ruin entrance, and that it changes and shifts from time to time.

There is, naturally, a trick to getting in.  If someone approaches the area of a ruin entrance while in the grip of some strong emotion, they will find it much easier to slip over the threshold to the Palace.  Upon entering, they’ll be deposited near the realm of the Sorrow of whatever emotion they were feeling at the time.

If a Sorrow has a lair in the mortal world, it will almost certainly have a link to the Palace, generally to the Sorrow’s personal area.  Sometimes there’s a literal door from the mortal world to their world.  Sometimes their lair in the mortal world *is* their lair at the Palace, overlapping both places at once.  It might be possible for a mortal to enter the Palace through a Sorrow’s lair, but that would, of course, mean invading a Sorrow’s lair.

Dangers

Aside from the Sorrows themselves, there could be literally anything wandering the halls of the Palace.  Escapees from personal realms, unfortunate mortals who have gotten lost (and maybe lost some sanity), random monsters that slipped in when a Sorrow was careless or bored… anything.

Since the Sorrows are all of roughly equivalent power, any mortal that is a guest of a Sorrow (rare, but it can happen) is theoretically under that Sorrow’s protection.  Theoretically.  While no one is likely to mess with the mortal in question while the Sorrow is present, it would be unwise for them to go wandering.  And some of the Sorrows are fickle creatures, likely to turn on "guests" at a moment’s notice.  Sometimes, they don’t see visiting mortals so much as guests as they do pets, playthings, or experiments.  Any unaccompanied mortal is seen as fair game.

Even if the Sorrows don’t notice any mortals wandering about, they’re still an ever present danger.  Just because the Sorrows can’t really do anything permanent to one another does not mean there is no conflict.  It can range from (relatively) harmless pranks, to outright invasions and wars where lairs happen to touch, and anyone in the vicinity would get dragged into the mess.

Origins

The origin of the Palace of Infinite Corridors is a matter of debate.  There are some who think it was always here, and that the Sorrows are just the ones who can use it best. 

Another school of thought suggests that the Sorrows create it and that it’s merely a function of their existance.  To be sure, the birthplaces of Sorrows are often tied to the Palace as either ruin entrances or lairs, a result of the scars left on reality by the forces that created them.  This is also supported by the control over the subjective reality of the Palace the Sorrows possess.

A third, and much more worrying theory is that it’s the other way round, that the Palace creates the Sorrows.  This idea is that the Palace is the manifestation of either some fell magic beyond mortal ken or the collective unconscious of the world at large.  Either way, it seeps through the cracks between the worlds into the mortal realm, eventually resulting in the birth of a Sorrow.

Of course, not even the Sorrows know for sure.  They don’t care where the Palace came from, only that it is.

Possibilities

Why would one want to come to such a place as this?

Maybe the unfortunate sods didn’t know what they were getting into, or it was an accident when they entered the Palace of Infinite Corridors.  Now they have to find a way out before they get noticed.

Maybe they think there’s something they want in the Sorrows’ keeping.  Maybe they’re right, maybe they’re not, either way, things are likely to get a little more interesting than they generally like.

Maybe they’re heroically (read, stupidly) trying to eliminate one or more of these demons, and decide to take the initiative and make the first move.

Maybe they’ve made "friends" with one of the Sorrows and are here as it’s guests.  Alternatively, a Sorrow might have brought them to the Palace without asking, out of sheer spite, curiosity, or boredom.  Either way, I’m sure it will end well.