Also, I guess Nicieza was just messing with me in that interview I gave him, when he said he didn't know anything about the invisible stuff.
I was wondering about that! Maybe he was asked to tie Underground together for some reason. Now it just makes Steph punching Babs and Tim all the more WTF and hilarious, since it makes it possible for that to be her. (And also raises the question of why she was working with the Penguin.)