Castle star Nathan Fillion has talk about show cancellation.Facebook/Castle

"Castle" showrunners Terence Paul Winter and Alexi Hawley are preparing big surprises for viewers. One of them could be the return of Jack Coleman as Senator William Bracken and his new moves against Richard Castle (Nathan Fillion) and Kate Beckett (Stana Katic).

Although the corrupt politician is not in a position to harm the mystery novelist and the detective, he could make a powerful return after the female lead announces her decision to run for New York State Senate.

The new development in the storyline could take viewers of the crime procedural drama to some unexpected turns, but they might not be pleased with it. According to a poll conducted by International Business Times, 70% of the fans revealed that they would love to see Katic's character as Captain.

The messages ranged from "She became a cop because of her mother's murder. It's been her dream to make captain and I don't believe as senate she would be able to work with Castle. Also I don't think she would want to run for senator after her experience with senator Bracken" to "I hope she becomes the new captain of the police dept."

Meanwhile, speculations also suggest that the creators of "Castle" might introduce a new villain who could either be related to Richard's disappearance or may have a character-specific mythology, according to Carter Matt.

But since there are no official details on a new cast member, fans of the ABC series will have to wait until 21 September to know more about season 8.