Boardwalk Empire" season 4 is set to return for another action-packed season on Sunday, September 8 at 9 PM ET on HBO. The HBO trailer has offered more detailed spoilers about what we can expect from "Boardwalk Empire" season 4.

The "Boardwalk Empire" season 4 trailer starts with the new rival to Nucky, Dr. Narcisse, asking "Do you know what power is? It is freedom and control over men who are lesser than you. This is my business." Dr. Narcisse is a gangster that controls Harlem and the first black character to be depicted in a position of power aside from Chalky White. We can see that Dr. Narcisse has dealings with both Nucky and Chalky White. The arrival of Dr. Narcisse is Atlantic City is clearly beginning to shake things up. Other figures like Arnold Rothstein appear to be discussing him and have dealings with him.

We also see a fan favorite, Al Capone, in the "Boardwalk Empire" season 4 trailer. Capone is rising to power and we see scenes that look almost like the St. Valentine's Day Massacre in which Capone and other gangsters were responsible for the murder of seven other mobster. However, it is still too early for that, "Boardwalk Empire" picks up eight months after the previous season in 1924. The St. Valentine's Day Massacre took place in 1929. Other scenes show Van Alden starting to involve himself more deeply in a life of crime, bootlegging, gambling and prostitution, "That is a business with which you are familiar," says Dean O'Bannion. Van Alden, now posing as George Muller has become involved in the Chicago mob, facing off against Al Capone's crew.

It seems that season 4 of "Boardwalk Empire" will focus a lot more on Chicago than Atlantic City. In one scene it looks like Al Capone has greater ambitions or is behaving recklessly at which point Johnny Torrio chastises him, "Do you want to take on the Chicago police? They'll send an army!" The next scene has uniformed officers with rifles bursting in. We don't see much of what is happening New York, aside from knowing that Arnold Rothstein and people like Joe Masseria are still around. Margaret continues to be conspicuously absent from the trailer and all other promo materials. We are starting to suspect that she could be dead or simply have left New Jersey and gone somewhere else with her family. In the "Boardwalk Empire" season 4 promo poster released we can see three characters front and center.

As Nucky looks out on Atlantic City in "Boardwalk Empire" season 4, he asks "You ever wake up and have a vague feeling of unease?" He then adds, "The only thing you can count on is blood." We can be sure that this season of "Boardwalk Empire" might be the bloodiest yet.

What do you think of "Boardwalk Empire" season 4 spoilers so far?

'Boardwalk Empire' Season 4 Spoilers: After 8-Month Gap, How Will A Demoralized Nucky Face The Most Powerful Gangster In Harlem? [REPORT]

"Boardwalk Empire' Season 4 Spoilers: Who Is Nucky's New Enemy In 'No Reign Goes Unchallenged' Trailer? [VIDEO]

"Boardwalk Empire' Season 4 Spoilers: Who Is Nucky's New Enemy In 'No Reign Goes Unchallenged' Trailer? [VIDEO]