Nucky and Chalky both begin the episode in jail, but only one of them ends the episode there. Nucky is bailed out pretty quickly, but Chalky stays to get thrown in with the other black prisoners, one of whom is a real hardcase. It looks like Hardcase is going to bait Chalky into a confrontation that won't end well for Chalky, but it turns out that being the Nucky Thompson of the black community makes you more than a few friends; the kind of friends who can help you beat hardcases senseless and then read you some David Copperfield to help you calm down.

Jimmy travels to New York for a meeting with Arnold Rothstein. He's looking to expand his business and wants Rothstein as a buyer, but Rothstein seems more interested in examining the schism between Jimmy and Nucky than actually committing to anything. Meanwhile, things are as frosty as ever between Jimmy and Lucky Luciano, but Lucky still invites Jimmy to a meeting with him and Meyer Lansky, who want to get into the heroin business with Jimmy. Later on, Jimmy baits-and-stabs a couple Lower East Side mafia types, which officially makes him more of a New Yorker than I am.

Back in Atlantic City, the Commodore gathers together all of Nucky's ward bosses -- two of whom, Jim Neri and skinny little puissant Patrick Ryan, were the ones who turned evidence against Nucky to the state -- and tells them to climb aboard the Commodore express. (The Commodore Express, by the way, has been freshly grease-painted about the hair and mustache, which is just the greatest thing that has ever happened, and is able to lift whole elephant tusks clear over his head.) They're all prepared to get with the winning team, except for Fleming, who is loyal to Nucky.

Margaret is obviously freaking out once she gets the news of Nucky's arrest. To her credit, she musters up her resourcefulness, dresses up like poor, Season 1 Margaret (even faking pregnancy!), and gets the state investigators to let her into Nucky's office. Later, back at home, Margaret answers the door to one Owen Slater, advance man for Nucky's imminent dinner guest, a Sinn Fein bigwig looking for a donation. Slater mistakes her for 1) the maid, and then 2) the maid's MOTHER, but he's cute and he's Irish and he charms the hell out of the maids.

Nucky returns to his office to find his ledger gone, and then just before Fleming has the chance to rat out his fellow aldermen, Nucky gets a call from Eli. With the Commodore over his shoulder, Eli declares civil war against his brother. Then the Commodore introduces him to Uncle Junior Muttonchops and ... the Secret Mason Elders of Atlantic City? This situation is developing ...

At Nucky's house for dinner, the Sinn Fein guy, McGarrigle, turns out to be a stiff prig, and he's mean and insulting to Margaret for assimilating. That's before Nucky shows up and satisfies the guy with booze and a check. The good news is that Slater is sticking around. After the Irish leave, Nucky is an open book with Margaret about the coup, though it's left to her to correctly intuit that Eli is among the betrayers. She also reveals -- duh -- that she took the ledger (and $20,000 in cash) before the investigators could find it. They burn the ledger, and it becomes clear that Margaret may well be Nucky's best asset.