Im in the aerodrome, at big set of gold doors that say I need a key to get in. Ive killed all the mobs, even ran back to start and back to doors to make sure. Everythings dead, no corpse had a key on em. What do I do?

The key should be in a chest, if you ignore the door and keep going down.

Directly opposite there is a stairway down (not the way you came in) follow it.

Ah thanks! I had started going down there but it started looking like it ran back into the way I came. Thanks

In my game there was no key. I went through that whole dungeon for nothing. I took a magic shaft.