Whoops! This is the kind of place that teaches you to enter Dungeons in turn-based mode. And notice that NWC turns you to the right when you enter, making it easy to miss the Ogre Magi behind you. Not fair!
You might want to do this Dungeon at a higher level, but you should be able to pull it off if you've just picked up Expert Alchemy in Alvar. You'll want to harden your weapons and quaff some Stoneskin potions first.
The basic Earth Magic Slow spell will let you out-maneuver your enemies, though it's hard to keep track of who's Slowed and who isn't. Boost your melee damage with Heroism and raise your Resistances against Fire, Air and Water. Use Bless and Fire Aura, but you should already know that.
Berserk, an expert-level Mind Magic spell, is also helpful. This will distract and weaken your enemies, but remember that you don't get Experience Points for Monsters that you don't personally dispatch. You may have just gotten Expert Mind, but the Clerical Magic shop in Alvar doesn't carry the book. You should have found a copy back in Smuggler's Cove.