We’re one episode out from the first season finale on AMC’s new post-Civil War tale of revenge on the railroad, “Hell on Wheels,” and like any great show, it continues to surprise and entertain on an upward slope with every new episode.

The man at the center of the story, a former slaveholder and Rebel soldier named Cullen Bohannon (Anson Mount) is trying, body by body, to avenge the death of his wife at the hands of Yankee soldiers, and now that the Civil War is over, Rebs, Yanks and freed slaves alike have congregated in the Great Plains to find work building the great transcontinental railroads. In the midst of his quest, he finds himself promoted to the head foreman of the Union Pacific railroad project and alternately threatening, fighting against and fighting with an educated, enlightened and angry freed slave by the name of Elam Ferguson (Common, aka Lonnie Rashid Lynn).

Bohannon is nearly hanged, shot, stabbed or pierced by Cherokee arrows several times in the first season, and he has an uncanny knack for besting considerable odds and turning the tables on his aggressors. Certainly the show has its “called it” predictable moments (like any time Bohannon somehow kills everyone who means him harm), but it’s no less enjoyable because of them. Common is an able actor, bringing an indignant and righteous air to his interactions with his mostly white coworkers on the railroad. Mount hasn’t shown a lot of nuance with his acting, as he’s mostly been in smoldering badass mode all season, but it’s effective. And it should be noted the cinematography, costuming and set designs for this show easily set a new standard for Western-frontier period pieces. I can just about feel the mud drying on my ankles every time an establishing shot shows the laborers trudging through the muck back at “Hell,” the circus/shantytown-like mobile tent town that moves a few miles with every new quota of railroad laid.

It’s a beautiful, grotesque, sometimes cliche but mostly exciting and engrossing period drama that touches on every aspect of frontier living from negotiating or fighting natives to post-slavery racism to paying off senators back east for more government assistance. OK that last one is probably most relevant to railroad tycoons, but still.

And speaking of Common, the rapper slash actor has a new album out called “The Dreamer, The Believer” on which he’s teamed back up with producer No I.D., who was the head beatmaker on most of Common’s early work. I must say both of the Chicago natives have improved their craft greatly since those days.

Common Sense, as he used to be called, had a somewhat sleepy, monotonous flow and a young No I.D. tended to augment that with monotonous, repetitive beats. Now I.D.’s compositions are much more dynamic and layered and Common has learned over the years to vary his flow and the tone of his voice (not to mention his subject matter) to suit the feel of the tracks. For instance, the track most other rappers seem to have chosen from the album to freestyle over, “Sweet,” displays both artists at a sort of fiery intensity that neither of them seemed to be able to register earlier in their careers.