The issue of contract negotiations has not yet been solved for the stars of ABC's Castle, but show runner David Amann is doing his best to ensure a smooth process.

'Castle's Beckett Confronts 'Question Of Children' After Big Kidnapping?

ABC has not yet decided if they want to renew Castle for an eighth season to air this fall, while stars Nathan Fillion (who plays Castle) and Stana Katic (Beckett) have their contracts expiring at the end of this season. This is obviously a predicament for Amann and company, but he told TVGuide.com this week that they are doing what they can.

"We're hopeful that everything gets resolved. In the meantime, we're just building the best end of the season that we can," he explained. "Obviously, we've thought about a bunch of different scenarios, but our main obligation is to our audience and to deliver great shows. That's what we'll be trying to do, and we think we have a bunch of them lined up all the way to the end."

'Castle' Boss David Amann Addresses 'Vanishing' Story Line & Exploring More 'Beckett Mythology'

Castle is coming off a big two-part episode that featured the return of Jerry Tyson (Michael Mosley) and Dr. Kelly Nieman (Annie Wersching). They will take a break from the drama next week with a lighter episode.

Amann said that it will be "a fun, classic Castle episode. It's basically murder on Mars. There's a Mars simulation with astronauts who've been locked away in a Mars environment for six months, and one of them is murdered. But none of them could have done it -- nobody could have gotten in."

The episode features Castle and Beckett donning spacesuits in order to talk to people. Amann said that moving forward there will be a theme of Beckett questioning her life decisions and goals.

"There is this kind of an ongoing theme for Beckett about what it is that she wants to do next with her life and her career. That's going to be something that manifests in the episodes moving forward," he shared.

Castle airs Mondays at 10 p.m. ET/PT on ABC.

Watch the promo for the next episode of Castle here:

Tags: Castle television ABC