In the series premiere, Montana marshal Seth Bullock executes a last act of justice and relocates to a gold-mining camp known as Deadwood, where he and partner Sol Star look to start a hardware business. Bullock soon crosses paths with another new arrival--legendary gunfighter Wild Bill Hickok--and clashes with the formidable boss of the Gem Saloon, Al Swearengen.

As suspicions arise that “road agents” may have been involved in the massacre, Swearengen takes a special interest in the health of its sole survivor, a young girl ministered to by the unlikely team of Doc Cochran and Calamity Jane.

Competition arrives for Swearengen in the form of Bella Union, a new gambling outfit from Chicago operated by savvy Cy Tolliver, Madame Joanie Stubbs and gambling guru Eddie Sawyer. Meanwhile Bullock and Star strike a deal with Swearengen on a lot for their store.

Swearengen directs Farnum to buy back the Garret claim; Alma prevails on Calamity Jane and Hickok for help; Hickok commissions Bullock in his stead; Charlie Utter leaves the camp; and Hickok’s run of luck at poker yields an unexpected return.

Swearengen transforms the Gem to a courtroom as Deadwood is forced to make its own laws to try a murderer; with Jane on a bender, Swearengen enlists Trixie to help Alma with the Metz child; Doc Cochran fears Cramed’s illness might threaten the camp.

Bullock encounters native resistance in his quest to bring a murderer to justice; Swearengen presses a resentful Farnum to keep tabs on Alma and Trixie; the camp fathers pool resources to dispatch riders after a precious vaccine and build a sick tent.