Image in-but-not-of Itself (cum ipsa absentia)

Meet Richard Castle, a successful mystery writer who killed his main character in his last book. But it seems that one of the admirers of his talent liked the books a little too much - a copycat appears in the city, committing crimes, copying with deadly accuracy the ways in which Castle killed in his works. And so our bored writer was called to the NYPD homicide department to help find the killer.