The indelible characters of the series are reunited after ten years to celebrate South Dakota's statehood. Former rivalries are reignited, alliances are tested and old wounds are reopened, as all are left to navigate the inevitable changes that modernity and time have wrought.

In the Season Three finale, Deadwood turns out to vote; Alma makes a deal; Utter receives one body for Hearst, who demands to see another.

Bullock holds an impromptu morning meeting to determine which emergencies warrant wiring him in Sturgis, where he and Harry are delivering campaign pitches. The first summons doesn't take long, as Hearst follows up Alma's close call with one that's decidedly more on-target. In the aftermath, Alma takes refuge at the Gem, again, while Trixie decides to take matters into her own hands. Langrishe has a falling out with Hearst, giving him little time to huddle with his new lineup of actors. Dismissing the likelihood of ever seeing 23 mercenaries promised by Hawkeye, Swearengen turns to Wu to deliver more reliable, if not quite weapons-tested, reinforcements from Custer City.

With the Sheriff out of camp, Alma is assailed by Hearst's men and as she never would have expected, shelter comes from Swearengen. Barrett is sent to the Gem, but Al resorts to old fashion methods of inquiring to his employers plans. Meanwhile, Langrishe recruits a new actor.

As Deadwood is overrun by Hearst's men, Bullock issues contingency plans to Martha. Wu is caught in a Pinkerton stampede and delivers a cryptic message, that is solved by the unlikeliest person, to Swearengen. Barrett makes Merrick pay for embarrassing Hearst in "The Pioneer", while Morgan Earp calls out one of the "Pistoleros". As night falls, Langrishe mines Deadwood's talent pool with an amateur-night performance in front of his future theater, financed in part by a "loan" from Alma's bank.

Merrick and Blazanov deliver the day's edition of "The Pioneer" around camp. A stagecoach arrives accompanied by the sound of gunfire as two strangers (Wyatt and Morgan Earp) come into town, unsettling the Sheriff and Al, who wonder if they're Hearst's men. Swearengen talks to Wyatt Earp, evaluating his story, while Fields prepares for his departure. Jack tells his ailing friend, Chesterton, that he will move him to the theater that day. Lastly, Hearst finds an unexpected doctor for his back problems as he awaits an important "package".

Bullock's proposal carries the day during a meeting held at the Gem to discuss the Hearst conundrum; Aunt Lou fears for Odell's well-being after his latest gambit; Fields is skeptical of Steve's offer to remain in camp; Cochran finds other uses for a tailor's swatches; Chesterton's illness postpones Langrishe's theater plans.

While Hearst still lies in jail, Al pays the Sheriff a visit, asking about last night. Sofia is worried about Mr. Ellsworth's absence, which saddens Alma even more. Bullock releases Hearst from prison. Aunt Lou's son, Odell, arrives in camp and Cy Tolliver presents Hearst with a method of setting his hands on Alma's gold claim. Trixie confronts Mrs. Ellsworth in regard to her drug habit, while Odell and Hearst prepare for a meeting to discuss the issue of gold. Al and Seth, worried about Hearst's reply, try to find an answer to their problem

As Tolliver tries to find a respectable employee suitable to be his liaison with Hearst, Swearengen tries to understand the reasoning behind Hearst's actions. The conflict becomes more tense as Dority and Captain Turner violently settle their differences. Bullock tries to finally settle the dispute between Steve and Hostetler and another murder brings Bullock once more face to face with Hearst, forcing him to take action. Trixie becomes suspicious of Alma's odd behaviour at the bank. Ellsworth and Alma have a close encounter that alters their relationship. Langrishe welcomes more arrivals from his theater troupe.

While Alma officially opens the bank of Deadwood, Langrishe asks Joanie whether she is willing to sell the Chez Ami, so he could make it into a theatre. Stapleton sets his eye on one of the new actresses in town and Jane receives a telegram from Fields. Hostetler and the latter arrive in camp and engage Steve with regard to the ownership of the livery, forcing Bullock to intervene. Meanwhile, Al delegates Adams to represent him in his affairs with Hearst and Tolliver.

New arrivals on the stagecoach usher into Deadwood: Jack Langrishe, a stage promoter and friend of Al Swearengen, and Aunt Lou Marchbanks, Hearst's longtime cook. Also returning to town is a newly westernized Wu, with news for "Swegin" about a soon-to-arrive group of imported Hearst workers. Recovered from her ailments, Alma decides to approach Hearst with a claim deal, despite Ellsworth's adamant objections. Bullock uncovers the truth about the Gem killings, and vows to put Hearst on notice. Hearst calls Tolliver's bluff, then offers him a "fresh start."

Captain Turner tips off Swearengen with a cryptic note to another bloody incident at the Gem; later, Hearst makes his intentions known in a more straightforward way. While Jane finds a captive audience for her oratory skills, the candidates for mayor and sheriff aren't as fortunate. Alma's health raises the issue of Sofia's stewardship and newly reformed Andy Cramed pays a visit to Tolliver, with a different agenda and outcome

Deadwood's first true elections are nearly here, with the offices of sheriff and mayor to be decided. Tonight, the candidates will state their cases to the townspeople. One of Hearst's Cornish workers is killed at the Gem, leading Swearengen to suspect that the incident was a staged Hearst power play. Ellsworth and Doc Cochran are alarmed by complications involving Alma's pregnancy. Star gains a new home from Adams' orchestrated foreclosure. Jane prepares to tell the camp's children about her experiences scouting for General Custer. Shocked by her inability to make a clean break from the gut-stabbed Tolliver, Joanie considers taking the easy way out. Hearst will give Bullock his political backing if Bullock promises to exert influence over certain areas of the camp.