In the Dark: Prologue.

Far beneath the sea, in a time distanced from our own, there is a great city. It rolls across the seabed on a score of mammoth treads, carrying within its massive arching dome half a million souls. It is surrounded by darkness, and is, itself, a thing of shadow; light is reflected off its dome, to conserve it for those within. Conservation is the key for this great underwater city, for there is so little to go around.

For the city, power is an eternally pressing need; to fuel its heat-generating engines, its light-producing lamps, and the hundred and one other necessities of a city. But the depths are cold, and so the city must travel, rolling from one thermal vent to another, staying while the heat is there, then rolling to another, praying that they will not run out of power before they get there.

It is an existence of extremes that the people of this city live; the stakes are ever high, for no more than a few could flee in the direst contingency. But still men live within, with their petty quarrels and disdain for the common good, and so mistakes - or worse - happen. Sometimes, nothing comes of them; but the worst of them could be the end of this city, and half-a-million people within.

My name is Sam Black, and it's my job to safeguard this city. It's never easy, but I have a feeling that before too long, it's going to get a hell of a lot harder.