Watch Castle Season 8, Episode 1 Online

After passing the Captain's exam in the Season 7 finale, Beckett was surprised with an offer to run for State Senate. In the action packed season premiere, Castle and Beckett are adjusting to Beckett's career change, when a call from a mysterious stranger sets off an explosive chain of events. There are two sides to every story, and this unique two-parter will explore the same story from each of their perspectives, first from Castle's side as he searches for Beckett. When mystery-thriller writer Richard Castle (Nathan Fillion) is called in to help investigate a series of copycat murders based on his books, he finds he enjoys the experience sufficiently to want to continue it. Pulling strings, he arranges to accompany NYPD Detective Kate Beckett (Stana Katic), claiming he wants to study and use her as a personality basis for his next book series. Once that initial case was solved, Castle and Beckett continued to investigate strange homicides in New York, combining Castle's writer intuition and Beckett's creative detective work. Over the past four seasons, Castle and Beckett's relationship has grown even stronger as they've dodged bullets, captured killers, and solved countless murder cases with their unorthodox partnership.