Although ABC's hit crime series Castle was sadly not invited to San Diego's fourth annual Comic-Con, it still has continued to build an increasing amount of interest for its upcoming sixth season, as new info has come out on episode three.

SpoilerTV reported that the respective installment will be called Need To Know, and the murder victim in the episode is said to be a Russian actress who is supposed to be "gorgeous," and starred in the film 2 Cool for School within the TV series' world.

According to Carter Matt, Castle is currently on the casting prowl for another potentially important character. The recurring role due to be cast is that of Frank "Sully" Sullivan, a detective.The site reported that the actor in the Sully role should be debuting on Oct. 7.

In other recent Castle chatter, executive producer Andrew Marlowe spoke about the impact that Castle's season 3 finale marriage proposal to Beckett will have on the dynamic between the two.

"Regardless of her answer, it is going to significantly change their relationship," he said.

More on Castle's cliffhanger marriage proposal to Beckett

Although no airdate has yet to be announced, ABC's Castle should be kicking off on either Monday, September 23 or the following week. Keep checking back for more of the latest details on the ABC series. A fan-made trailer of the upcoming season can be watched below.