[3] In the episode, the regular cast find themselves in a computer simulation of a Wild West town, facing a gunfight against the Four Horsemen of the Apocalypse.
Dave Lister takes delight in using a salvaged functioning artificial reality (AR) machine to have sex with various female game characters, but is forced by Kryten to suspend his latest endeavour.
Seeing him losing, Lister, Rimmer and Cat opt to help him by entering his dream through the AR machine, utilising the abilities of characters from a Wild West-styled video game.
Upon arriving and getting Kryten to recognise them, the trio distract the Apocalypse Boys to give him time to create his antidote, escaping the dream when the virus infects the AR machine and takes away their characters' special abilities.
When she received the ambitious script for "Gunmen..." she sent out a memo that all production for the episode be stopped immediately, because she believed it too difficult to film, too costly and too time-consuming.
[10] One reviewer described the episode as "an excuse to transport the characters to a Wild West landscape, with results just as contrived as those on the original Star Trek but considerably funnier.