‘Shades of Blue’ Season 2 Episode 4 spoilers: Wozniak faces demons from his past; ‘Daddy’s Girl’ reveals his connection with Ayres [VIDEO]

Cast member Ray Liotta speaks at a panel for the NBC series "Shades of Blue" during the Television Critics Association (TCA) Cable Winter Press Tour in Pasadena, California, January 13, 2016. Reuters/Mario Anzuoni

Things get darker as an investigation goes deeper on the fourth episode of “Shades of Blue.” On the upcoming run of the NBC series, titled “Daddy’s Girl,” Matt Wozniak (Ray Liotta) finds himself dealing with ghosts from his past as he tackles a drug case. It also gives a glimpse of his previous life, including his daughter’s death.

The March 26 installment also exposes his relationship with Councilwoman Julia Ayres, played by “Breaking Bad” actress Anna Gunn. The reason behind Wozniak’s loyalty with Ayres is finally going to be known – fans would remember that he refuses to mess with her despite FBI Agent Robert Stahl’s (Warren Kole) order.

Other characters from the series who will appear prominently on the episode include Harlee Santos (Jennifer Lopez), Carlos Espada (Vincent Laresca), Tess Nazario (Drea de Matteo), Marcus Tufo (Hampton Fluker), Michael Loman (Dayo Okeniyi), Gino Anthony Pesi (James Nava) and Cristina Santos (Sarah Jeffery).

Spoiler alert! This update contains more "Shades of Blue" spoilers. Read on at your own risk if you have not watched the latest episode.

TV Guide reports that also on Sunday’s episode, Harlee launches her own investigation on the controversial mayoral candidate after she realises that Stahl will pull out all the stops to arrest Ayres. Harlee wants to find out if Stahl’s accusations are true: if Julia really has an active connection with the mob.

“Shades of Blue” also posted a sneak peek for the March 26 episode on its official YouTube page [watch below]. In the clip, Cristina calls Stahl, offering information to help track down her dad. Meanwhile, Wozniak’s team catches some students who are suspected of carrying some drugs. He tortures someone, asking where the stash is but he doesn’t get any answer. Later, Wozniak seems to have taken things too far – Harlee is seen desperately calling for help.

Spoilers also suggest that Harlee and Wozniak struggle to keep up with Michael Bianchi (Ritchi Coster), a high-profile mafia figure. Fans would remember that the two arrested Bianchi for aggravated assault. “Daddy’s Girl” also features guest stars Tyler Elliot Burke (Felix), W Tre Davis (Devonte), Jabari Gray (Special Agent Rice) and Mimi Michaels (Caroline Winston), according to the Internet Movie Database, or IMDb.

Find out what happens next on “Shades of Blue” Season 2, which airs in the US this Sunday at 10/9c on NBC. In Australia, the series airs every Thursday at 8:30 p.m. on Universal Channel.