Castle, from this trailer, looks like a crime procedural, a fairly popular format among the viewing public in the US. It's a story of mystery-thriller writer who discovers that a copycat has been doing the crimes from his books for real. And he offers to help police solve the cases.
I tell you what right now --- I am not feeling the female lead and I don't know why that is.
Here's the trailer to Castle, which will be airing beginning March 2009 on ABC.