Emily Deschanel, David Boreanaz Emily Deschanel, David Boreanaz

Bones returns to the air Thursday after a three-month hiatus with 11 straight weeks of murders to solve. But will those episodes be the show's last?

Although Fox has announced several renewals for the 2015-2016 TV season, Bones' Season 11 pickup has been delayed by contract negotiations with stars Emily Deschanel and David Boreanaz. "We have started conversations with them and we're very hopeful that Bones will return," Fox TV Group Co-Chairman Dana Walden told reporters at the Television Critics Association winter previews in January. "We love the show. It's been so meaningful to the studio and nothing would make us happier than doing another year."

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Even if the show is renewed, it seems likely that its days are still numbered. (Fox execs have said they are currently negotiating a one-season deal with the stars.) But at least the stars seem committed to continuing. "I feel like we still have stories to tell," Deschanel recently told TVLine. "I think everyone's interested in continuing to tell the story. I don't know how much longer after Season 11 it would go, but it'd be nice to explore it for at least one more year."

Even though a Season 11 seems possible at this point, the uncertainty surrounding the show's future made crafting the end of Season 10 difficult for executive producer Stephen Nathan. "We had planned a couple of really good cliff-hangers for the end of this season to lead us into Season 11," he tells TVGuide.com. "We weren't really able to do that because if by some chance the show did not come back, it would have been such a disappointment to the audience, who has stayed with us for so long, to just drop everything. So, we weren't going to do that."

Instead, Nathan had to build an ending that could give some closure but also leave the door open to continue. "We're threading the line," he says. "Because we haven't gotten the official word yet... we have to operate under the assumption that this could be the end of our relationship with Booth and Brennan and these people. So, it was that balancing act of having their lives continue and having their lives conclude in some way for us. We can always pick up where we left off, but it was difficult."

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Even so, Nathan is excited about the wide-ranging cases the show will tackle in the coming weeks. Although the show will touch on serious topics — Thursday's premiere revisits the team's emotional reaction to the death of Sweets (John Francis Daley) earlier this season and a later episode will once again explore Booth's gambling addiction — other episodes involve murders in the world of miniature golf and even at the gang's favorite diner.

"We're really kind of going from the sublime to the ridiculous, " Nathan says. "Some episodes hopefully will be emotionally wrenching and some episodes will be pretty absurd. The entire season comes together in the last five or six episodes, where everyone's past comes back to determine the future. We're going to change everything up."

Indeed, perhaps the biggest story line in the back half of the season involves Brennan's second pregnancy. (Once again, the show wrote Deschanel's real-life pregnancy into the show.) "This time we see the emotional consequences of the pregnancy far more than the physical," Nathan says. "Any pregnancy forces a couple to look at their lives and see the life that they are living, that they are bringing this new person into. You realize how enormous this is — they joy, yes, but also the responsibility, the fear, and the desire to protect this child. This second child puts everything under a microscope, and consequently Booth and Brennan are forced to look at who they are and how their life is now to be lived."

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But even those characters who aren't expecting a child will be forced to do some reflecting as well. Hodgins (TJ Thyne) and Angela (Michaela Conlin) will take a look at their marriage, as well as possible next steps in their careers. Cam (Tamara Taylor) will have to consider putting her future on hold when Atrastoo (Pej Vahdat) decides to return to Iran to deal with his ailing brother. "The end of this season is a tremendous reexamination on the part of everyone," Nathan says. "Prior seasons, we've seen our group coalesce, both as individuals, as couples, and as a community. At the end of this season, we'll see that while those bonds are strong, while one can never sever those kinds of connections, that doesn't mean that life goes on as before. And it won't."

So, does that mean Bones fans shouldn't expect a happy ending to the season — and possibly the series? "We can leave the show in a place that seems quite happy but is not necessarily free of tension and apprehension," Nathan says. "I think it has been our intention to do both. So, it's not really a cliff-hanger, but there is a cliff."

Bones airs Thursdays at 8/7c on Fox.