There's a girl in a mask killing bad guys, but it's not Katherine Harlow.

She's disappeared and a less experienced but enthusiastic wannabe has sidled in to take her place. You can bet that when Kat returns to reclaim Hollow Girl's mask, there's going to be a reckoning, and not just with her 'Little Sister'.

Because Detective Collins has crossed a line, leading to an inevitable and bloody final showdown.