Season 2 contains twelve episodes and aired from March 6, 2005 to May 22, 2005.
Tensions flare as the camp faces an uncertain future. Al Swearengen taunts Seth Bullock over his relationship with Alma Garret, and the resulting confrontation between sheriff and criminal turns violent. With a new business venture on the horizon, Joanie Stubbs and Cy Tolliver await the arrival of some fancy new whores on the next stagecoach, which also bears two important reminders of Bullock's past.
Alma and an increasingly self-destructive Bullock face an abrupt decision on their future. At the Gem, while Swearengen readies for another showdown with Bullock, infighting between Silas Adams and Dan Dority yields more feed for Wu's pigs. Doc Cochran is surprised by Calamity Jane, who has returned to camp in a state of inebriated deterioration.
Francis Wolcott, chief scout for a powerful mining operation, arrives to shake up the status quo - beginning with Cy Tolliver. Swearengen's lackeys fret as he refuses visitors and medical attention. Joanie's new partner, Maddie, reveals she's also running a game as their new brothel, the Chez Ami, services its first customer.
Doc contemplates a procedure that could cure Swearengen - or kill him. Bullock attempts to settle into domesticity, while Sol gets a new student bookkeeper - Trixie. Alma cuts ties with Sofia's tutor, Miss Isringhausen. Joanie and Maddie argue over the business. The County Commissioner's arrival spawns rumors about the camp's future and legal ownership of the gold claims.
Swearengen is on the mend as Alma begins to take ill - mostly in the mornings. Cy is suspicious of Joanie and Maddie's operation, and makes an unexpected discovery about George Hearst's agent, Wolcott. Bullock attempts to control an outlaw mob and protect the Commissioner, who directed Merrick to print a provocative statement regarding gold claims.
Alma proposes opening a bank with the help of Sol Star. A new schoolteacher arrives in town, much to Merrick's delight. Much to Wu's dismay, new Chinese whores arrive. Wolcott's inner demons wreak havoc on Joanie's whorehouse, testing his alliance with Cy. Bullock attempts to keep order in the camp, and at the same time settle into family life.
Joanie discovers what happened at the Chez Ami and confides in Charlie Utter. Swearengen meets with Alma regarding Miss Isringhausen's allegations...and her connection to the Pinkertons. The town leaders convene to discuss pressing issues, but neglect to invite E.B., the mayor. By way of a strange circumstance, Utter comes into possession of Wild Bill's final correspondence.
Wolcott offers on the claim of two ornery brothers, and reports to Hearst on their progress overall. Miss Isgringhausen strikes a deal with Swearengen, who discusses his options with a friend in a small box. Alma receives very different proposals from both Mrs. Bullock and Ellsworth. A Russian telegraph operator arrives in camp, and Joanie befriends a reluctant Jane.
Bullock makes a connection with his son. Swearengen, who has entrusted E.B. to spy on the new telegraph operator, stokes rumors of an annexation of the camp and amends his agreement with Miss Isgringhausen. Cy aims to unburden a troubled man of his bloodstained money. Alma and Martha come to an agreement, and a tragic accident befalls the camp.
When Doc delivers a dire prognosis, one family suffers and the entire camp stands vigil. Merrick avails some private information to Swearengen, who enlists Star and Adams to help con the newly returned Commissioner Jarry. Andy, a former Deadwood pariah, offers himself as the camp's new minister. Trixie pressures a distraught Alma to accept a beneficial proposal.
Death in the camp spooks the superstitious, and the impending funeral causes much sorrow. Cy is convinced that Andy - who will officiate at the service - is back in town to run a game. Wu asks Swearengen to back him against the "San Francisco cocksucker". Bullock encourages his wife to stay in Deadwood.
A marriage occurs against a backdrop of murder and negotiations for elections and the camp.
- A Lie Agreed Upon: Part I
- A Lie Agreed Upon: Part II
- New Money
- Requiem for a Gleet
- Something Very Expensive
- E.B. Was Left Out
- Childish Things
- Amalgamation and Capital
- Advances, None Miraculous
- The Whores Can Come
- Timothy Olyphant as Seth Bullock
- Ian McShane as Al Swearengen
- Molly Parker as Alma Garret
- Brad Dourif as Doc Cochran
- W. Earl Brown as Dan Dority
- John Hawkes as Sol Star
- Paula Malcomson as Trixie
- Dayton Callie as Charlie Utter
- Leon Rippy as Tom Nuttall
- William Sanderson as E.B. Farnum
- Robin Weigert as Calamity Jane
- Sean Bridgers as Johnny Burns
- Bree Seanna Wall as Sofia Metz
- Jim Beaver as Whitney Ellsworth
- Jeffrey Jones as A.W. Merrick
- Kim Dickens as Joanie Stubbs
- Powers Boothe as Cy Tolliver
- Anna Gunn as Martha Bullock