 Holly invents a new drive system called the "Holly Hop Drive", declaring that it can theoretically get "Red Dwarf" back to Earth in an instant.When Arnold Rimmer, Dave Lister and Cat decide to use the new system, it transports the ship into a parallel universe, and in proximity of a parallel version of "Red Dwarf".Onboard, Rimmer, Lister and Holly encounter their female counterparts – Arlene Rimmer (Suzanne Bertish), Deb Lister (Angela Bruce) and Hilly (Hattie Hayridge) – discovering that in this universe, women are the masters and superior gender, while men fought for equal rights.