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.

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 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.