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?