Two key roles for Bones season 9 have been cast recently.

Freddie Prinze Jr. will be appearing in a recurring arc in season 9 of Bones, according to a Wednesday report by TVLine. He will be playing a covert CIA agent named Danny who used to work with Seeley Booth (David Boreanaz). Danny will take a special interest in Booth and Temperance "Booth" Brennan's (Emily Deschanel) murder investigation in the season premiere.

Prinze is married to Buffy the Vampire Slayer star Sarah Michelle Gellar, which Boreanaz also starred in.

The ex-priest who reenters Booth's life has also been cast. Mather Zickel (House of Lies, I Love You, Man) has been cast as the ex-priest, named Aldo Coulter. Enstars previously reported that this ex-priest would reunite with Booth at the beginning of season 9 to help fix his problem with serial killer Pelant (Andrew Leeds) and also mend his relationship with Brennan. Boreanaz broke the news that Zickel would be joining the cast on his Twitter account Wednesday night.

Bones executive producer Hart Hanson told TVLine recently that Aldo Coulter is someone who "knows Booth better than [Brennan] does." He also described the priest as Booth's "ex-confessor when he was a sniper in the Rangers." In the season premiere, Booth will enlist in Aldo, who reportedly runs a bar when viewers first meet him. He will talk to the priest after feeling "Catholic guilt" from recently ending his engagement with Brennan.

The first episode of season 9 will be called The Secrets in the Proposal, seemingly mirroring the season 8 finale episode title, The Secrets in the Siege.

Bones will be premiering on Monday, Sept. 16 at 8 p.m. on Fox.

Watch this clip of Hanson and fellow executive producer Ian Toynton discussing what's ahead for season 9 of Bones:

Tags: Bones Spoilers