Sigh, yes, let's get the bad news out of the way first. Supergirl will be airing on CBS, which is the network which has brought you such diverse programming as Cold Case, Without a Trace, Criminal Minds, NCIS and The Mentalist, CIS, CSI: Miami and CSI: NY, and CSI: Cyber. You don't get a show on this channel without it being a police procedural unless it's a sitcom. And given the state of the last semi-high-profile superhero sitcom, nobody wants that. So the set up of Supergirl will involve the character's classic comic book origin, and Kara Zor-El will be spending at least part of her time in a costume complete with S-shield and cape. But most of the time, she'll be solving crimes the old fashioned way. The premise of the Supergirl series is that she gets enlisted by a super-secret agency where her sister also works...to help them protect the citizens of National City from sinister threats. So she's essentially a deputised secret agent who solves crimes. She'll be putting on her costume to scrap with people when the budget can allow it, but expect lots of clue-piecing and the like too.