• David Boreanaz and Emily Deschanel attend the 'Bones' panel during Comic-Con International 2016 at San Diego Convention Center on July 22, 2016 in San Diego, California.

David Boreanaz and Emily Deschanel attend the 'Bones' panel during Comic-Con International 2016 at San Diego Convention Center on July 22, 2016 in San Diego, California. (Photo : Getty Images/Alberto E. Rodriguez)

The final season of the Fox crime drama "Bones" is set to feature an exciting plotline to close off the series' last chapter. Latest spoiler news hint of a new villain that will test Booth (David Boreanaz) and Brennan's (Emily Deschanel) mettle, while Zack's (Eric Millegan) arc will impact the plotlines of remaining episodes.

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"Bones" Season 12 episode 1 featured a dramatic twist that unveiled Zack's true intentions toward his former mentor Brennan despite kidnapping the Jeffersonian forensic anthropologist. Aired on Jan. 3, Tuesday, Zack's actions was meant to keep Booth's wife out of trouble while a killer is on the loose.

Booth and Brennan also discovered that Zack is innocent of the crime that he was convicted of, where he was sent to a mental institution instead of a prison. Featured in the earlier season of "Bones," the former Jeffersonian intern admitted to killing the lobbyist although he was manipulated by Gormogon to assist the cannibalistic serial killer in finding his target.

In an interview with TV Guide, co-showrunner Michael Peterson commented that Booth, Brennan and the rest of the Jeffersonian team will be hard at work looking for evidence to exonerate Zack. The former intern's storyline will also remain a vital plot in upcoming episodes where Zack's friends will be "fighting for his future."

Booth and Brennan's revelation that Zack is innocent will also impact the story arc of other characters such as Hodgins (T. J. Thyne) and Angela (Michaela Conlin), according to the co-executive producer. Viewers can also look forward to seeing episodes that will feature the deceased character Sweets (John Francis Daley) specifically his journals.

Apart from trying to prove Zack's innocence, Booth and Brennan will also have their hands full with a different kind of serial killer. Peterson shared in an interview with TVLine that the said villain will launch a "coordinated attack" against the crime fighting married couple.

Peterson added, "This [villain] is a little more action-oriented, more military-based. And this one is born out of revenge more than any other storyline."

"Bones" Season 12 airs every Tuesday on Fox. Watch a teaser clip for the upcoming episode below: