As Castle wraps up its first season tonight, fans are wondering about this show's status on ABC's fall schedule.

While we won't have an answer until the network's upfronts presentation on May 19, here's what star Nathan Fillion said on Friday about the prospects of season two.

"The reaction we've been getting from the network is super positive, and the reaction from the audience has been positive. That's the most important thing."

Regarding tonight's finale, "A Death in the Family," Fillion told Zap2It that it involves the murder of a plastic surgeon, along with Castle digging around Beckett's past a bit too aggressively (and Alexis, pictured above with her father, attending the prom).

"This is an episode where we see just how clever or appropriate Castle can be when it comes to where you draw the line, and how far you go before it's too far," the actor said.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.