"Castle" is expected to return with a new mythology. The Season 7 is likely to introduce new characters associated with the new story-arc as well as will be introducing guest stars for the episodic murder mysteries. As the premiere episode of "Castle" Season 7 will pick where it left off at the end of Season 6, the investigation will revolve around 'what happened to Castle' and in all likelihood new characters will appear to help solve this mystery.
The Season 6 of "Castle" wrapped-up with Castle's car in the ditch and in flames. The car accident and the missing status of Rick Castle will get Hamptons police involved, as TV Line reports that for the premiere episode, police sergeant of Hamptons is being guest-cast. In addition to the police sergeant, a doctor, a shrink and a coast guard captain will make an appearance.
The TV Line also reports about a character called Henry. This character, who reportedly has a guest-starring role, has been described as someone who is "highly intelligent" and an "unassuming gent." The report says that Henry is "deft at blending into a crowd." TV Line also hints about the possibility of Henry being a "nemesis" of 3XK who may appear with a new face thanks to Dr. Niemann.
The premiere episode is a two-parter, according to the report. David Amann, who was recently promoted as the showrunner of "Castle," is writing the premiere episode of "Castle" Season 7. The two-part episode will be directed by Rob Bowman.
It is almost confirmed that Castle is alive and Nathan Fillion has signed on to appear in the upcoming season. Andrew Marlowe, who has been the showrunner through the show's last six seasons, will continue to be associated with the show that he created.
Speaking about the upcoming season premiere episode, Marlowe said to TV Line that they would be picking up in real time, as "We feel like, given the way we left off, we have an obligation to start exactly where we ended."
"Castle" Season 7 will premiere this September. It consists of 23 episodes.