Bones EP Previews Monday's 'Dark' Episode and 'Very Surprising' Season 9 Cliffhanger

Bones Season 9 FinaleWith a Season 10 pickup firmly under Bones‘ belt, producers of the Fox procedural are moving forward with Plan A and ending Season 9 with a doozy of a cliffhanger.

“We’re ending the year in a very surprising way,” teases EP Stephen Nathan. “Two different stories converge and it throws Booth and Brennan’s work relationship into turmoil and causes big, big changes for our people.”

Per Nathan, one of those plots centers on “a promotion that seems to exist within the FBI and they have their eye on Booth to fill this position,” while the other storyline involves a certain invisible serial menace. “The Ghost Killer [arc] becomes far more complex and conspiratorial, and very well might lead back to the FBI.”

PHOTOS | The 19 Best Kisses in TV History

In the more immediate future — specifically, March 10 when Bones returns from its winter hiatus to reclaim its Monday-at-8/7c perch — Booth will be dealing with an unresolved CIA issue when Freddie Prinze Jr. reprises his role as super-spy Danny Beck.

“We wanted to do an episode where we really saw the friendship between Booth and Danny, and also touch on the things that kept them apart,” explains Nathan of the atypically “dark and action-filled” outing. “What kind of a friendship exists when one person’s life is all secrets? And Danny’s got a lot of secrets.”

PHOTOS | 24 TV Characters Who Are (Probably) About to Die

The episode does have its lighter moments, courtesy of a B-story that finds Brennan buying a life insurance policy. “Her rates are far more than Booth’s, and she doesn’t understand why since both of them are essentially doing the same job,” Nathan previews. “She’s penalized for going into the field and Booth is not. It’s a way for us to explore the difference between their [professional] partnership and the marriage.”