The season finale of "Castle" is expected to delve into the question of why Rick became a mystery writer.

TV Line reports series creator Andrew W. Marlowe, who wrote the Hollander Woods entitled finale, recently opined, "One of the areas we haven't explored is why Castle (Nate Fillion) became a mystery writer. Was there something that created a fascination with murder and with death and with bodies?"

In the Season 7 episode, which will air on May 11, Det. Kate Beckett (Stana Katic) also seems to have reached a crossroads in life, with Marlowe adding the hard-charging officer appears at a point where she needs to "do something more, something a little bit bigger."

It all leaves her facing a series of critical life choices that could change the course of almost everything.

While the series has yet to be officially greenlight for another season, rumors have persisted that Katic's status with the show remains very much up in the air. Both Katic and Fillion's contracts are up at the end of the season, but Fillion recently inked a new deal pending the show's ongoing status.

Earlier this year, Katic told TV Line, "If the character is complete, if there is nowhere else to go creatively, then I think it's better to stop when you're on top. [F]or me it's about art over finance."

Meanwhile, former "Fringe" star Lance Reddick is also slated to star in the Season 7 finale. His status with the show was recently revealed after co-star Penny Johnson (Captain Victoria Gates) tweeted out a photo of him on the set of the show.

The episode is also expected to star former CSI veteran Wallace Langham and to delve into Castle's Season 6 disappearance on what would have been his wedding day. Some of this season's earlier shows touched upon that mystery, but more recently most episodes have steered clear of the issue.

"Castle" also stars Molly Quinn as Alexis Castle, Jon Huertas as Javier Esposito and Seamus Dever as Kevin Ryan.