I don't know if it's a bug or an awesome game mechanic. I couldn't find a key to open the Black Ominous Gate. So after being bored & frustrated I started launching spells at it. After 23 level 7 Fireballs, Flares, & level 5 Winterbreaths the gate was destroyed.
And the key was just to the west of that door in a room behind a source monster...
