One of the biggest mysteries "Castle" has yet to solve is the detective's six-month long disappearance. While morsels of clues were dropped in the previous season, the show still hasn't offered a complete explanation as to what really happened to Castle when he went missing. This will change come "Castle" season 8.

According to executive producer Alexi Hawley, more pieces of the puzzle will be found in the upcoming season. During a chat with Entertainment Weekly, Hawley guaranteed that viewers will get answers.

"This year, we really do want to get into what happened when he was gone in a way that hopefully ties a lot of the threads of mysteries of seven seasons together in an unexpected and exciting way," Hawley said.

It remains to be seen if season 8 will fully unmask the mystery, or if it will just drop enough details and clues that will ultimately help fans complete the puzzle. 

In other related news, the new season is also welcoming a baby. The new bundle of joy is not Castle and Beckett's though. The baby is Ryan's and he or she will be his second kid and will be the younger sibling of his first child, little Sarah Grace. 

"Ultimately, that's going to make Ryan even more paranoid and more excited about trying to make more money," executive producer Terrence Winter told TV Guide.

His will to provide for his growing family will cause a bit of rift in the office, too.

"When he sees Beckett rising up in the ranks, [Ryan and Esposito] realize it's time for them to start looking at their futures, which is going to create some tension and conflict between them," he explained. 

Winter did not mention anything about Castle and Beckett getting busy with parenthood, although this is something some fans have been dying to see. While he emphasized that the new season will explore the "next evolution" of their relationship, it will involve conflicts rather than diapers. 

"Castle" season 8 airs Sept. 21.