Reading the post regarding the surface map and subterren map gave me an idea for the late-game part.
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Imagine that the catacomb as it is now is a barrier of sorts, a hundred level Labyrinth, and below that is a whole new world altogether. You've probably heard of underground cities and countries. This is the real deal.
A thousand years ago, give or take a couple of century, this... Underworld broke through the dimensional barriers seperating the two worlds, the result of which sent shockwaves across the whole of reality, weakening it enough for other holes to appear. The main tear, however, ripped the world apart just where Crossgate is now situtated, and through it they sent their armies.
They were beaten back, of course, or we wouldn't be sitting here right now, but not without cost.
Before they came, there was no kingdom, no empire. Just a lot of tribes fighting and surviving as best as they could. The Underworld invasion changed that. The tribes were forced to band together just to live to see tomorrow. And from this core, the empire, or at least the begining of it, was formed. They joined their forces together and forced the Underworld army back, taking terrible losses, but was finally sucessful.
Their mages then combined their magics together, welding shut the rip in space-time as best as they could. But it was a patch job at best, and it was consistently being tested from below. Then someone came up with the idea of building a Labyrinth, to slow down and confuse them, and so they did. After a few years, and several layers later, the threat from the underworld was diminished enough that a small community was able to form around the work site, and a small village was formed. This was the start of the City later known as Crossgate.
After about fifty layers or so, the Underworld threat was vurtually gone, but fear of them kept the workers busy, until an even hundred layers stood between them and the underword. The CrossKeep was built then, to watch over the Labyrinth and stand guard against them.
And watch they did, even as the empire grew and fell, to be replaced by other empires, other kingdoms. Until eventually the memories of the horrors were forgotten, washed away by the rivers of time, and no one could remember the purpose of the castle.
Crossgate had by this time grown into a small city, its remote location attracting those who were hiding, refugees of one war or another, and also those who had reason to hide, smugglers, slavers, and the likes. Adventuers too were drawn to Crossgate to challage the Labyrinth, conviced that there must be some vast treasure hidden within. And so the city grew, gaining a reputation through its trade of curious items and creatures sometimes found within the Labyrinth, its original purpose all but forgotten.
It would have remain that way for the next thousand years, but for your father. He found mentions of the Underworld in old records, and was intrige by it. He was determined to find this Underworld, and to plunder its riches. (The legends he had heard mixed up mentions of adventurers looking for treasures, and the old Underworld. Naturally he assumes that the riches are found in the Underwold.)
Through sheer dumb luck and determination, he actually found the way through to the Underworld, and decided to return to the surface to make a proper expertition out of it. When he returned, however, the Temple caught wind of it, and had him killed. (Which Temple... now that's a good question.) The rest, I believe you know.
So what will you do now? Seal the Labyrinth? Or follow the path of your father.
What will you find there? I don't know. Would their inhabitants make good slaves? Maybe you should try, and find out. It could be the key to all your dreams, or it could be your worst nightmares......
