The largest part of the original cast makes an appearance in the film. So include Ian McShane, Timothy Olyphant, Molly Parker and Brad Dourif. Daniel Minahan takes, just like in the series, the director.
Deadwood is about the life in the eponymous town in the American state of South Dakota at the end of the nineteenth century, when the gold rush was. The series, aired between 2004 and 2006, got rave reviews and won eight emmys. In 2008, HBO has been two Deadwood movies, but those are never published.
The film would be in the spring of 2019 in American cinemas in the show.