On tonight's new episode of 'Boardwalk Empire,' Sally Wheet tips Nucky off to the heroin piggybacking on his shipment of rum from Tampa, further complicating the bigger issues plaguing him at home -- with Chalky White and Dr. Narcisse on the precipice of war, whose side will Nucky take? "White Horse Pike" brings long-simmering conflicts to a boil in both Atlantic City and Chicago, and there's no shortage of bullets flying tonight.

"Cast your lot, is it so?" -- Dr. Valentin Narcisse

"When push comes to shove, what are you gonna do?" -- Nucky Thompson

What Narcisse is doing on the north side of Atlantic City is not much different than what Nucky has done in the past. As the mayor of the Boardwalk, Nucky was bootlegging the very same alcohol which he promised to crack down on for his constituents. Narcisse is importing and distributing the very heroin that plagues his people with addiction, then sells them on relief. These men have manufactured circumstances in which they are both the villain and the hero, making the public wholly dependent upon them. And we see that on a small scale tonight, too, when Narcisse is granted one small moment of humanity: comforting Chalky's daughter, recently dumped by her fiance on the eve of their wedding day. It's a scene that drips with dread -- we know how unpredictable and sinister Dr. Narcisse can be, and his moment of kindness is somehow more disquieting than when he removes the mask, as he did when he battered Daughter Maitland.

"White Horse Pike" is an episode packed with momentum and unease, and everyone is casting their lot this week. They've made their choices, and now come the consequences and the revelations of betrayal. Look, as much as we'd love to believe that Eli wasn't going to turn on his brother (again), we all knew it was coming. When push comes to shove, Eli is going to protect his family, even if it means forsaking one for the sake of the others; the needs of the many outweigh the needs of the few, after all. But what Eli didn't count on was his own son's involvement with Nucky's operation, so distracted he's been by the increasingly imposing Agent Tolliver, a man who slips into different names as if they were a change of gloves -- an echo heard in the way Narcisse introduces himself to Mabel as Richard Pastor. These men, who breathe lies as easily as air, are the real danger. And it's no coincidence that both of them fire off pretty important shots tonight.

Tolliver shoots one of the bootleggers up from Tampa with the supply of rum and Masseria's hidden heroin, leading to a confrontation between Nucky and Meyer Lansky that puts Nucky deeper into the Chalky-Narcisse feud than he wanted. We've watched Nucky try and skirt this conflict, so concerned with manners and criminal civility -- his own code of ethics, if you will. He's tried to stay out of potentially fatal conflicts this season, but you can't go about being an organized criminal with just one toe in the water, and the heroin trade gives him the shove into the deep end that was coming one way or another. Faced with the choice of forfeiting a chunk of the profit to which he's entitled or giving up his friend, Nucky does what Nucky does best (and what most high-level crime bosses do) each and every time: he tries to have his cake and eat it, too.

Which brings us to the shot fired by Narcisse tonight -- after Chalky and his men open fire on Narcisse and his, Chalky takes a hit. We also learn where Nucky has chosen to employ Richard Harrow, and placing him at the Onyx Club to keep an eye on Chalky is one of the most brilliantly effective moves we've seen from Nucky in recent memory. While Chalky thinks that Nucky isn't being the friend he needs to be, Nucky puts someone like Richard on his side and arranges a police escort out of town to avoid giving his friend up to Narcisse. But Eli's not the only one betraying Nucky, and when the mayor flips for Narcisse, Chalky narrowly escapes with his life intact one more.

Michael K. Williams really knows how to play a gangster with many shades, giving depth of character that goes beyond plot and circumstance to something more subtle. We see the vulnerability in his eyes even when he talks tough, and a single frown or smile from Chalky can tell us everything we need to know, and hint at so much we don't. These scenes in the last few weeks in which Chalky has almost lost his life are thrilling -- we know he's capable of surviving, we hope he's as smart as we think he is, and yet there's still that chance he could die because anyone can bite it at any second. That's the nature of HBO crime dramas, and we've been trained as viewers to anticipate the worst in moments of utter quiet and calm. But knowing what's coming when the character doesn't makes it that much worse. Chalky's life is still on the line, and I'm not sure what sort of plan Nucky has -- not only does he have to deal with a traitorous mayor whom he himself placed in office, but he also has to contend with Masseria and Narcisse, perhaps the deadliest combination this show has seen.

Back in Chicago, Al Capone gets a little too eager about expanding his role in Johnny Torrio's business (and Van Alden seems to be fully integrated into the Capone gang). It's no surprise then, that Torrio tries to put the rabid dog down by having a crew open fire on the whole building, and if it weren't for our buddy Van Alden, the remaining two Capones would have gone the way of their brother. Having Capone comment that it's good that Johnny got out of the room when he did is a nice touch -- he's become so oblivious and his ego so bloated by all the cocaine and booze, and the removal of O'Banion has given him that extra pep in his step. Unfortunately for Al, it's always the people closest to you that will be your undoing.

That's something Nucky knows a little about -- but one hand doesn't always know what the other is doing, and right now he's so consumed by this Narcisse and Masseria business that it remains uncertain how long it will take him to see the betrayal in his own home. How will he deal with Eli betraying him once again? And is it too late for Eli to back out of the deal with Agent Tolliver now that he knows the very son he's set out to protect might be beyond his protection? What are you gonna do when push comes to shove?

Speaking of which, elsewhere this week: Margaret makes a deal with Rothstein to tip him off about those Anaconda Realty shares in exchange for a nice, safe home for her and the children. Also: Rothstein still really loves his milk and cake.