Alexi Hawley and Terence Paul Winter took on a challenge when they were handed the reins of ABC’s Castle, a seven-year-old show, back in May. Now the duo are facing a new challenge: crafting an end for Season 8 amid uncertainty whether stars Nathan Fillion and Stana Katic, whose contracts are up again, will return.

The show is currently shooting Episode 15, the script for Episode 16 is being finalized, and the writers are breaking Episode 17. “We’re definitely getting to a point where we need to figure out what Episodes 21 and 22 are, which is why we are having these discussions now,” Hawley said during ABC’s TCA party Saturday night.

Just last spring, Castle was in a similar situation. “Last year (creator) Andrew Marlowe wrote the finale not knowing if they would come back, and this year we knew we could possibly do the same thing — have a nice conclusion and still set up something we can launch into if there is a season 9,” Hawley said. “I think going out with a cliffhanger of sorts always helps you when you come back. When we came back this year, it had a conclusion last year, and I think ultimately it was a little harder for us to get out of the gate because people didn’t have anything driving them back.”

Still, Hawley and Winter will not leave fans hanging. “Everything that has been set up will come to a conclusion this season,” Winter said. That includes the LokSat mystery.

While they have their hands full with Season 8, Hawley and Winter have an idea where they want to go in Season 9, which is return to the show’s roots after a serialized eighth season.

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“This season was a little bit of a transition, getting Castle into the PI office and setting that world up for him to give him that drive,” Hawley said. “We wanted to wrap up a lot of the threads of different conspiracies, Beckett’s mother’s murder, Castle’s missing time. We wanted by the end of Season 8 to have gotten through all those — hopefully in a compelling and satisfying way — so Season 9 can be more about the case of the week, going back to the fun of solving the case of the week and not have the luggage of past conspiracies.”

Hawley and Winter were encouraged by ABC president Paul Lee’s statement at TCA that the network wants Castle to continue for more seasons. They also would like to see the show’s original stars back.

“We feel like the show has a lot of life left in it, and we want it to be with the same cast going forward,” Hawley said.