The end comes for every television show, no matter how popular it was. If it has franchise potential, then spin-off talk begins almost immediately. ABC's Castle has been running for eight years and been very popular in its time, but the end or, at the very least, a serious revamping, seems to be in order. Stars Nathan Fillion and Stana Katic are out of contract and it seems to be up in the air if either return to the long-running show. When a show grows a little long in the tooth, as Castle has, there is always a desire from the head brass to trim the budget. All of this has led to speculation about a possible spin-off. ABC has admitted this is something they've looked into, in case the show's stars don't return.
One popular idea with fans seems to be the side-kick spin-off idea centering around Detective Beckett's two subordinates, Ryan and Esposito. The two side characters have had one of TV's most noteable bromances in recent years and are fan favorites. According to EOnline, actor Seamus Dever, who plays Detective Ryan, thinks that a show based around the two characters is a good idea, "I've always thought that Ryan and Esposito would make fantastic spin-off material. From the beginning, Jon Huertas and I have a really good rapport, great dynamic, and we have a lot of fun together. I mean, we're one of the only procedurals on ABC, so it's like hey, you need a procedural? Espo and Ryan, they're going to solve crimes just like they do on Castle!"
If there is a Castle spin-off, it will actually be the second one tied to the show. According to Wikipedia, in 2014. ABC announced that a Derrick Storm project was being developed. Derrick Storm is the fictional character of the fictional mystery novelist Richard Castle. And before you ask, yes, there have been novels tied to the show. Castle debuted in 2009.
