First Castle Season 5 Promo! "They've Finally Crossed the Line" Tweet July 19, 2012 by Wetpaint Entertainment Staff Related: Castle, Previews , Season 5 Credit: YouTube Check out the first Castle promo for Season 5, and get ready for all new episodes starting this fall! RELATED: When Does Castle Season 5 Premiere? Castle Season 5 Spoiler: Esposito Reconnects With an Old [Spoiler]! Castle Season 5 Spoiler: Will Alexis Interfere With Castle and Beckett’s Alone Time?