Larian Studios Forums Divinity - Original Sin Divinity Original Sin - Help/Tips/Tricks White Witch prison

I've got the Elemental staff after killing Boreas(?) and now I am stuck in front of the ice prison with the White Witch inside it and don't know how to free her. I have cleared the whole Hiberheim, only an imp left and I have no clue what to do next, please help!

Thx to the steam forums I found the answer: You just need to DRAG AND DROP the Elemental staff onto the Lava fountain (forge) at the NE corner of the map. A fire elemental spawns and you receive a special rune which you have to USE in front of the prison.

Half of the "fun" in this game is googling, It's just ridiculous.

The staff told you what to do with it when you picked it up.