Plus on Minus

Collect cannon accumulators in the White Fortress and bring them to Agnes de Desirae.

Hey there! I'm Agnes, the Portal Keeper, and you are my new assistant.
I have a very important task for you. We need to restore the Portal, and it requires an energy supply. We can get some accumulators from the siege cannons on the walls. There is plenty of energy in each of them!

I need the energy spheres. Preferably, all of them.

Excellent! Now I just mustn't mess up the polarity, or we are going to end up in the Astral.