Emily Deschanel, David Boreanaz Emily Deschanel, David Boreanaz

Mortality is definitely on Dr. Brennan's mind on the Season 8 finale of Bones.

After watching Cam (Tamara Taylor) almost lose her boyfriend on the Fox drama's penultimate episode, Brennan (Emily Deschanel) is more focused than ever on making sure Booth (David Boreanaz) comes home alive at the end of the day. "The outbreak put a seed in Brennan's mind about how delicate our lives are," Deschanel tells TVGuide.com. "She can't help but internalize ... how devastating it would be to lose Booth. That ... plays a big part in the season finale."

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But perhaps the biggest question for fans is whether Booth and Brennan will come any closer to marriage, a topic that's reared its head several times in recent episodes. "The notion of marriage is again brought up in the finale," Nathan teases. "That's been a big part of the past season and a half and we would be remiss if we didn't examine it in the finale. If you thought the pot was stirred [this season], the pot... overflows and messes up the kitchen floor in the season finale."

Does that mean Brennan, who has spent much of the season wrestling against her scientific rationale, may finally give into her emotions? "There are big changes happening to Brennan," Deschanel says. "People can go their whole lives and never change who they are, but Brennan has really done work to change who she is. And circumstances in life have changed her without her intention."

So, will Brennan finally pop the question? "Brennan may be open to things she wasn't open to in the past," Deschanel teases. "Brennan has come a long way in how she views Booth and possibly how she views marriage. She definitely takes some action in regards to her future with Booth."

Bones' Season 8 finale airs Monday at 8/7c on Fox.