On the next "Person of Interest," a bunch of new villains will rear their evil heads. 

Executive producer Jonah Nolan told TVLine that a "clusterf--k of villains" will target Team Machine in episode 12, including Vigilance and Control. 

Nolan said the theme for the second half of the season will be "escalation."

"As taxing, difficult and ultimately lethal as the battle [with HR] was, that was just the beginning of the challenges put in front of our heroes," Nolan said. 

Executive producer Greg Plageman added, "We're going to see these various entities jockey for control of The Machine or at least something commensurate with it," triggering a situation "where Root starts to take matters into her own hands."

As for Reese (Jim Caviezel), he is still reluctant to come back into the fray after Carter's (Taraji P. Henson) death. "The loss of Carter created a rift between our guys on Team Machine as well as disillusionment on Reese's part," Plageman said. "Something much bigger has to happen if he's ever to come back into the fold."   

On the last episode, a devastated Reese went to his father's bar in Colorado, where Fusco (Kevin Chapman) found him. Meanwhile, Finch (Michael Emerson) and Shaw (Sarah Shahi) met Control (guest star Camryn Manheim), and discovered there was a second Machine. 

Michael Emerson told TVLine that Root (Amy Acker) is on to something that the rest of the team is unaware of. 

Emerson said "that line from her [Root] made my hair stand on end, because she clearly know things that we don't know."

"She's a confidante in the Machine in a way that no one else is, so I'm sure Mr. Finch lays awake at night wondering what the heck she meant," he added.

He also said that Team Machine may eventually see Root's usefulness. "Mr. Finch is warming to her, a bit," Emerson said. "She's proven certain things, and it's not all bad. But it's all crazy."

On the next episode, "Aletheia," "Finch and Sam try to save Arthur Claypool from Control without Reese's help, since he is still MIA along with Fusco."

"Aletheia" airs Tuesday, Jan. 7 at 10 p.m. on CBS.