The abandoned temple of Bhaal underneath Baldur's Gate has not been a secret since the Bhaalspawn crisis.
What is less known, are the tunnels leading all the way down to the Underdark, and to a certain ruined city, full of undead and worse.
Only recently breached by brave adventurers exploring the Underdark and it's secrets, rumours told of undead things of horrible power, killing many an unprepared adventurer, and only the most stubborn of them ever breached the city proper.
But now, months after the initial discovery, adventurers have reported the absence of the more powerful undead. At the same time, rumours carpet the cities and tradeposts of the Underdark, of Mind Flayers running scared in the lowest pits of the Lowerdark, gathering armies to combat some unknown threat from the mysterious "utterdark", that some equal to the Plane of Shadows.
Too many coincidences, perhaps, for it to be a coincidence. Dark times ahead, most certainly, for the city of Baldur's Gate, with it's armies depleted and coffers running low.
Who is to say, what the future will bring?