Hey guys. Castle Season 4’s official poster is now out. I am glad to share it with you. The poster looks mysterious, but, with the ending of Season 3, lots of people are wondering if there is going to be Caskett, as in maybe Detective Kate Beckett (Stana Katic) will hear what Richard Castle (Nathan Fillion) said when she was dying, and maybe they will become a couple or an item. So, tune in on September 19th, on ABC, at 10/9c to catch the first episode of Season 4!