Gage Rowdy has always lived one life. Kill or Be Killed is her motto. The only thing that has ever kept her alive that and the oh so charming company of the Riddler.
George Digger Harkness is known around the Aussie parts as Captain Boomerang becoming bored with the banks he's already robbed he moves to America banks liking the thrill.
When these two meet, people die, things expolde, and for Digger;Gage gives up her life of crime.
When Amanda Waller catches wind of them none of that matters.
Lighting always strikes twice.