Red Dwarf is a British comedy franchise, which primarily comprises ten series, of a television science fiction sitcom. It aired on BBC Two between 1988 and 1993 and from 1997 to 1999, gaining a cult following.
Two years into the trek back to Earth, Holly invented the Holly Hop Drive to get them back to Earth instantly. However it backfired and they ended up in another dimension. There he met and fell in love with Hilly a female version of himself. On the return to their universe Holly had a head change to look like Hilly. He remained "a she" for the next three years until Kryten's nanobots stole Red Dwarf and restored Holly to his former self.