This Karen Millen double breasted trench coat with large buttons was seen several times in Castle season 1 and season 2. It's the coat that started my obsession with Kate Beckett's vast outerwear collection. Side note: Wouldn't it be fun to have Will return now that Rick and Kate are engaged?
Castle: See what happens when I leave you alone. Beckett: Babe, I wasn't alone. When they were interrogating me, the only thing that kept me going was thinking about you. About our future, the wedding. You were with me the whole time.