Holly discovers the Holly Hop Drive which will take the Red Dwarf to Earth instantly.  However, when they put the drive into action they move into a parallel universe instead.  They wind up in a female dominated universe with female versions of themselves (except for Cat who has a Dog version of himself).  After drunken revelry, the two Listers wake up in bed.  Lady Rimmer begins to wonder if Lister might be pregnant, the male one...