'Chicago P.D.' season 4 episode 11 spoilers: Squad investigates independent special police force; showrunner speaks on Kenny Rixton's arrival

Intelligence looks into the actions of a private police force operating outside of the CPD on the upcoming episode of NBC's procedural drama "Chicago P.D." season 4.

Titled "You Wish," next week's episode will see the team investigate another police force. According to the official synopsis, a mutilated sex offender is found dead, but it is unclear if he was a victim of sexual assault, self-mutilation or hate crime. As Intelligence begins to question individuals connected to the case, they find themselves up against a private "special police" force. The squad later discovers that the organization may be responsible for covering up illegal activities. Elsewhere, Halstead (Jesse Lee Soffer) tests Jimmy's (guest star Tony Crane) DNA to confirm if he is indeed Lindsay's (Sophia Bush) biological father.

Change has been a prevalent theme this season, considering the departure of some notable characters. Following the exit of series regular Brian Geraghty and frequent recurring guest Samuel Hunt, November's fall finale saw the departure of Jon Seda to become a series regular on the upcoming spinoff "Chicago Justice." Viewers will also be saying goodbye (at least temporarily) to series regular Patrick John Flueger, whose character begins an undercover mission on the next episode.

Filling Flueger's spot is "Revenge" actor Nick Wechsler, who will be in the series for a multi-episode arc as Voight's former gang unit colleague Kenny Rixton. In a recent interview with The Hollywood Reporter, showrunner Matt Olmstead hinted that people in the unit are more than interested to know what Kenny's story is.

"If he was a former protege of Voight's from the gang unit, then does he represent the old Voight, which we knew from 'Chicago Fire,' which was the kind of no-rules person which Voight has evolved from?" Olmstead said, adding, "So the journey for his former protege is can he also make that transition? Or is he stuck in a certain methodology that is far from being with Voight back in the wild west of the gang unit?"

The fourth season of "Chicago P.D." airs every Wednesday night at 10 p.m. ET on NBC.