Hizon opened the Goblin Foundry to adventurers three days after Brannik returned.
He did not announce the coming dungeon battle, while it was unlikely there was always a chance that the fungal dungeon had contracted adventurers inside Max's dungeon. The adventurers entering the new instance believed they were testing another attraction in the Undercity. Hizon used their attempts to find problems his own creatures had learned to avoid.
The first party broke a steam line in the upper workshop and filled an entire corridor with scalding vapor. Goblin workers knew which emergency valves to close. The adventurers did not, and the vapor concealed them long enough to bypass a defensive position.
The second party used ice magic to jam two moving partitions at once. The mechanisms survived, but the goblins operating them could not force either wall to move.
