January 1920. On the eve of Prohibition, Atlantic City's Treasurer, Nucky Thompson, condemns alcohol at a Women's Temperance League meeting, where he is noticed by Margaret Schroeder, a pretty, pregnant housewife who comes to him for help in getting her abusive husband Hans a job. Later that evening, the duplicitous Nucky privately tells his ward bosses about the opportunity to make huge profits selling bootleg liquor. At a countdown-to-midnight blast at Babette's Supper Club, he assures Jimmy Darmody, a recently returned WWI vet, that his appointment as "Man Friday" to the new Chief Clerk of the Fourth Ward, Paddy Ryan, will lead to bigger things. Jimmy, meanwhile, has higher aspirations and ends up making an alliance that could have dire consequences for both him and Nucky.

Nucky deals with the fallout from Jimmy's rogue heist, sending Eli to sow the seeds of doubt in the mind of Margaret, who seeks help in the wake of her husband's demise.

An unlikely witness to the woods massacre threatens to expose the perpetrators, sending both Eli and Van Alden rushing to the hospital. Margaret starts a new job at an upscale French dress shop at the Ritz, while Chalky's team pays a heavy price for taking over Mickey Doyle's bootleg operation.

In Chicago, Jimmy bonds with one of Johnny Torrio's prostitutes, Pearl, and finds himself increasingly at odds with the hot-headed Al Capone. Back in Atlantic City, Nucky looks to leverage his political relationships with ambitious U.S. Senator Walter Edge and Jersey City Mayor Frank Hague, while Eli and Chalky go to extremes to interrogate a local KKK leader.

On the day of the annual St. Patrick's Eve dinner, Nucky deals with Eli's oratory ambitions, as well as a group of disenchanted "Leprechauns". Feeling ignored by Nucky, a frustrated Margaret feeds Van Alden information. In Chicago, Jimmy copes with the aftermath of a vicious attack orchestrated by Torrio rival Charlie Sheridan.

After the brazen robbery of one of his ward bosses, Nucky turns up the heat on Lucky Luciano. An emboldened Margaret stands up to Lucy at the dress shop and accepts an offer from Nucky to change her circumstances. In Chicago, Al's frustration over family issues spills over into his relationship with Jimmy, who scores points with Johnny Torrio for a bold power play involving Sheridan and the neighborhood of Greektown.

After his father Ethan is injured in a fall, Nucky uses the opportunity to refurbish his childhood home. On a double-date with new friend Annabelle and her beaux, Margaret tries to get Nucky to open up about some painful childhood memories. During a visit to an army hospital, Jimmy befriends disfigured vet Richard Harrow, whose sharp eye proves invaluable. Van Alden gets a lead on the woods massacre.

Nucky visits Chicago for the Republican National Convention, where he finds himself intrigued by the candidacy of Warren G. Harding over more established candidates. The D'Alessio gang moves in on Nucky's territory at the expense of Eli, who has been watching over his brother's affairs. Margaret finds herself entangled in Nucky's business affairs, while Van Alden struggles with his wife's desire for a child. Rothstein prepares for legal trouble over his role in fixing the 1919 World Series. Nucky asks Jimmy to return to Atlantic City to reinforce his position.

Nucky is forced to readjust his political alliances with a Democratic mayoral candidate promising to wipe out corruption. Jimmy returns from Chicago to deal with the D'Alessio gang, which has allied with Rothstein to import European scotch through Atlantic City, but is arrested by Agent Van Alden for the massacre in the woods. Margaret intercedes with Nucky on Madame Jeunet's behalf, while Angela finds her romantic and artistic ambitions halted by Jimmy's return.

Nucky asks for Margaret's assistance in backing his mayoral candidate with the passage of women's right to vote, leaving her conflicted about her role. Doyle switches sides back from Rothstein, which leads Nucky to conspire with Chalky against Lansky and the D'Alessios. Angela witnesses Jimmy's violent side against her photographer friend, and considers leaving Atlantic City for good in the aftermath. Van Alden grapples with his emotions, and has encounters with both Margaret and Lucy.

"Paris Green" is the 11th episode of the first season of the HBO television series Boardwalk Empire, which premiered November 28, 2010. The episode was written by supervising producer Howard Korder and directed by Allen Coulter.

Nucky faces Election Day in Atlantic City and pulls out all the stops to keep power in Republican hands. Torrio brokers a discussion between Nucky and Rothstein to resolve their growing gang war, as well as Rothstein's looming federal indictment over the World Series. Both Jimmy and Eli voice their growing resentment towards Nucky, and find they have an ally in the Commodore. Van Alden seeks a sign on whether or not to leave Atlantic City, but receives unexpected news from Lucy. Margaret weighs new information about Nucky's first marriage and her uncertain future to make a final decision on her role in his life.

Nucky is shocked by an insurrection among his inner circle. An attack threatens Chalky's life and livelihood. Margaret deals with her son's problems. Angela vies for Jimmy's affection. Van Alden shows his wife around town.

Despite being publicly embarrassed by legal trouble, Nucky's biggest concern may be holding on to his private army in a battle for control of Atlantic City. Meanwhile, Jimmy pitches a business deal to Arnold Rothstein in New York, but may have more in common with Meyer Lansky and Lucky Luciano. Margaret draws on past experience to retrieve some valuable information, Chalky clashes with a fellow inmate, and an Irish nationalist comes to town looking for support.

The Commodore throws his weight around with the Coast Guard to disrupt the delivery of alcohol, which creates an opportunity for Owen to demonstrate his value to Nucky and a struggling casino. Meanwhile, a letter dredges up painful memories for Margaret, Nucky calls in a favor with the U.S. attorney general, Meyer and Lucky learn the price of power, and Lucy searches for ways to cure her loneliness.

During Mayor Bader's birthday party, Nucky's attorney comes up with a solution that might help Nucky in his election-rigging case. With a liquor surplus likely, Jimmy and Mickey travel to Philadelphia to search for buyers while Nucky makes a surprising deal to try and get alcohol into Atlantic City. Eli is concerned over the Commodore's ability to lead. Margaret decides to give her staff bonuses. Chalky is cornered while at work and home. Owen takes his munitions expertise and uses it. Van Alden's agents set their eyes on Mickey's warehouse. Richard lets his guard down in the name of art. And Gillian thinks of the first time she was ever with the Commodore.

After a dispute with his enemies, Nucky brings in a surprise guest speaker at a Memorial Day dedication for war veterans. Running out of options, Eli questions his allegiances, but it ends up sending him deeper into the hole. Nucky hires a new lawyer. Jimmy is taught a lesson by one of the Commodore's men that he won't soon forget. Richard decides to go hunting in the forest.

Nucky tries to set up a risky liquor delivery to Philadelphia. Later, Attorney General Daugherty sees a problem that might complicate Nucky's case. Jimmy finds a new mentor in Leander Whitlock who is the Commodore's lawyer. Margaret finally goes to confessional. Lucy continues to struggle with loneliness while Van Alden tries to settle his conscience.

Margaret has a family reunion. Owen gets even with a rival. Van Alden recognizes the hierarchy of the law. Jimmy wonders how a decision will affect the future.

In the wake of a personal loss, Nucky solicits advice on his political situation from Arnold Rothstein, while Eli remains suspicious of his brother’s actions. Nucky finds himself in the unfamiliar position of showing gratitude toward a federal agent. Angela meets a new friend at the beach, and eavesdrops on her husband’s treachery. Nelson gets a nanny. Nucky approaches Owen with an overseas proposition. Jimmy flexes his muscles, at Mickey Doyle’s expense.

Arriving in Belfast, Nucky and Owen meet with IRA leaders with a barter proposition. Meanwhile, in Atlantic City, Jimmy and his partners broker a deal with George Remus for his “medicinal” alcohol before taking a break to see/hear the Dempsey fight. Margaret frets when Emily’s illness takes a turn for the worse. Dunn Purnsley orchestrates a worker’s strike at the Ritz. Waxey Gordon takes action against Manny Horvitz in Philadelphia, and Randolph and Clifford Lathrop grill Halloran about Nucky’s past.

Undercut by Nucky, who has a new source for alcohol, Jimmy and his partners look to cultivate a new revenue stream in Atlantic City. With the peak tourist season approaching, the Commodore’s crew faces a choice in dealing with the city’s striking workers; either negotiate or fight back. Fearing that sin has led to misfortune, Margaret approaches Father Brennan with an “act of devotion.” Nucky gets a new lawyer. Van Alden faces an uncertain future. Manny Horvitz takes exception to a debt payment.

With Margaret pondering the consequences of sin, Nucky prepares her for a worst-case scenario as Esther Randolph plays out her trump cards. Jimmy revisits his college days with Angela and Gillian. Mickey Doyle chafes at sharing his liquor profits. Eli refuses to cop a plea. Nelson's past comes back to haunt him, tipping the scale in Nucky's favor.

Esther Randolph's case is weakened by the sudden death of one witness and the sudden marriage of another. Jimmy turns away from the influence of others, including his mother. Nucky, acting the family man to Margaret, faces a difficult, bottom-line business decision.