SPOILER ALERT: This story contains details of the Season 9 finale of Bones.

The Comic-Con panel for 20th Century Fox TV’s Bones was chock-full of spoilers for Season 10 (watch the trailer below), but a balance of optimism and vagueness pervaded when it came to how long this series will be on the air. As Fox Networks Group Chairman/CEO Peter Rice mentioned at TCA, Fox would love more seasons of Bones, but it boils down to Emily Deschanelrenewing the contracts of leads Emily Deschanel and David Boreanaz, which are up at the end of the season. “To go 10 seasons like this was inconceivable, and I know these guys feel the same,” said executive producer Stephen Nathan. “They are so inspirational and kept these characters alive. … Hopefully you’ll see us going to 20 seasons.”

Related: ‘Bones’ Renewed For Season 10, Will Return To Mondays In March

Boreanaz responded to Nathan’s optimism by closing his eyes, a sign that 20 is just way too long.

“I like to work in the present on what we’re working on now,” Boreanaz said about his future with the show. “It’s always a moment-for-moment thing for me. Whether it’s Episode 500 or Episode 1,000, it’s just about the moment at hand.”

san-diego-comic-con-logoBoreanaz will direct the 200th episode, which EP Nathan says “will be an odd one.” Earlier in the panel, Nathan gave the lowdown on Season 10, which opens four months after season 9: Special Agent Booth (Boreanaz) is in jail and Dr. Brennan (Deschanel) is doing everything in her power to spring him and to get to the bottom of the conspiracy. “Booth is in a state of confusion, in terms of where he fits with the bureau and his family,” Boreanaz said.

Said Nathan: “The conspiracy on the show goes on for decades. These two can catch a murderer, but it doesn’t mean they stop all murder. We’ll put a stop to the conspiracy in the first few episodes.

“We’re also going to deal with the world of psychics and immigration in Season 10,” he added, “but we’re doing it from a human trafficking point of view; there’s an issue of slavery.”

Nathan also said he hopes Cyndi Lauper will return as psychic Avalon Harmonia, but she’s unconfirmed.

Here’s the Season 10 Bones trailer that premiered at Comic-Con: