[General Nosaj]

The door is meant to be locked so there is no way out. Spells like fireball and cloudkill work well against the umber hulks who are not that strong. Iron golems are slower than the hulks so you could try drawing the hulks out first, finnish them off and then deal with the golems. If you have any animate dead spells or the like you could use them as cannon fodder as you deal with the golems but it will be tough. Is the 2nd Malavon spell resistant? I can't remember.