Bat'zuls Prison

This is from the last mission of the Virgil Takiros (Cap Au Diable) Strike Force. I won't spoiling it too much, but this where you'll find the AV.

And for the Masterminds do this Strike Force, the lava if like catnip for your pets. Keep a tight lease on your pets, otherwise they will try to defeat all of the lava. Even to the point of diving in and melee'ing the lava.