It is drama series about life on the wards of Holby City Hospital, following the highs and lows of the staff and patients. It began with eleven main characters in its first series, all of whom have since left the show. New main characters have been both written in and out of the series since, with a core of around fifteen main actors employed on the serial at any given time. Season 20 is first released on 2 Jan, 2018.