"Castle" stars Nathan Fillion as Richard Castle, Stana Katic as NYPD Detective Kate Beckett, Susan Sullivan as Martha Rodgers, Molly Quinn as Alexis Castle, Penny Johnson Jerald as NYPD Captain Victoria Gates, Tamala Jones as Medical Examiner Lanie Parish, Jon Huertas as NYPD Detective Javier Esposito, and Seamus Dever as NYPD Detective Kevin Ryan.