What does 今更何を知ろう mean here?

Question

今更何を知ろうというのだ。早く『シン』を倒せばよかろう。

It's from a video game Final Fantasy X. These are the words of the Grand Maester Maika, the party comes to him, but he didn't expect their arrival.

My translation:

What would you like to inquire about now?

The volitional form 知ろう in this case defines their will to know?

Answer 1

Yes 知ろう is the volitional form of 知る, so it's literally "want to know". 今さら is "at this (late) point (of time​)". Also note that this is an authoritative statement without any keigo.

今更何を知ろうというのだ。
What do you want to know after all this?