In the next episode of "Gotham," Detectives James Gordon (Ben McKenzie) and Harvey Bullock (Donal Logue) hunt down an insane cop killer who wears a pig mask.

The trailer for the upcoming installment titled "Hog Day Afternoon" was released just recently and showed Gordon and Bullock going all over the city and finding murdered policemen wearing pig masks. The cops appear to be sitting on benches, dead and motionless while crowds gather in shock around them. The detectives seem like they found a lead in the case and search an abandoned factory. It is also apparent that it may be housing a considerable number of pigs and may be the headquarters of the killer who is called Pyg.

All of a sudden, there is a loud explosion which hurls Gordon and Bullock a few feet away. The pigs are startled and start running scared. In the last scene, Gordon comes face-to-face with the mad killer Pyg as he chillingly says, "Oink, oink." It remains to be seen what Pyg will do to Gordon and Bullock since they also belong to law enforcement which the madman detests.

In the last episode, Bruce Wayne (David Mazouz) went after Ra's al Ghul (Alexander Siddig) who was in prison for killing Wayne's friend. When the young boy entered Ghul's cell, he wanted to kill him but could not because he knew it was not right. Ghul demeaned the boy for not being able to kill him and said that he was weak.

The old villain then taunted Wayne for having no guts which caused his friend to die. Wayne got angry and suddenly stabbed Ghul with the ancient blade. As expected, the young boy began to regret his actions for committing the murder

"Gotham" season 4 episode 6 will air on Thursday, Oct. 26 at 8 p.m. EDT on Fox.