I'm at a loss. I searched all the sewers, I don’t understand how to get to the location with the final boss.

There are no crossings in the Temple of Baal area, or did I not look well?

I was sure that I needed to get to the Upper City, and climb into the sewers there. But the Upper City is inaccessible, the gates that lead to it are closed.


Thanks to Larian for Baldurs Gate 3 and the reaction to player feedback