The Quantum Skipper was a very powerful yet small and portable device, designed to break down the barriers between different dimensions.
When activated, it could allow the user to "skip" into the body of his or her counterpart in an alternate reality, and therefore allow for exploration of The Multiverse.
The boys from the Dwarf first found this device at an abandoned quantum research station. It was damaged when first brought aboard Red Dwarf, and caused all kinds of trouble as Kryten attempted to fix it. A month after finding the device, a miscalculation of the settings tore a hole in space-time, and resulted in a Quantum Anomaly near to the ship. The anomaly caused the Dwarfers to undertake the opposite of every action they intended to do, as universes where they decided differently filtered back into their own through the anomaly.
After Kryten had finally repaired the Quantum Skipper and used it to close the anomaly, the Dwarfers had a discussion as to who would use the device. Dave Lister did not want to leave since he had responsibilities as the last human in this universe, Kryten wanted to stay to look after Lister, and Cat wanted to stay because this universe already had him in it, and so he saw no reason to leave it. Arnold Rimmer, who had feeling depressed, decided that he would use the skipper to look for a reality where he was more successful and happy. Lister joked that, even with an infinite number of universes, finding a universe where Rimmer was not such a loser that would take some finding.
Kryten explained that any universe travelled to would be a random one, but would be fairly close to their own reality, and therefore not too different. There would also be a recharge time needed for the device between skips. Rimmer gave a farewell speech to his crewmates - simply exclaiming "See ya!" - and much to his and to the delight of everybody else, Rimmer disappeared in a flash of blue light, and a high-pitched electronic sound.
After using the quantum skipper for the first time, Rimmer found himself in White Corridor 159 on a version of Red Dwarf three million years earlier, where the Cadmium II radiation leak had not yet occurred, the original crew were still alive. He was still a hologram, yet apparently similar to his original hologram iteration with a large "H" on his forehead, and wearing his old beige uniform. As he struggled to come to terms with the fact that the crew were still alive, he passed Bradley, a Science Officer, who ordered Rimmer to get back to work on Z Shift. Soon after, Rimmer also realised that Holly was still the ship computer, seemingly appearing older yet still mentally unstable. After conversing with Holly for a while and wandering around the ship, the Cadmium II radiation leak began to occur. Rimmer spent some time conversing with Captain Hollister, who was stuck in a jammed escape pod. Just before the flames hit Rimmer, the device finished its recharge, and Rimmer beamed into another reality.
Rimmer then found himself on a version of Red Dwarf that was much more similar to his own, and where he was again wearing his usual blue uniform, yet where he was good friends with Lister instead of them hating each other. This was because, unlike in his reality where Lister is a working-class slob, Lister here is more upper-class and anally-retentive, much like Rimmer himself. Just as Rimmer thinks that he might stay in this dimension, the alternate version of the Cat enters - who is this reality is a loud, overbearing and oversized rat simply called The Rat. Rimmer is horrified, especially when he learns this Red Dwarf is full of Rattus sapiens. Rimmer then beams out of "Rat World", only to find a version of Red Dwarf that is seemingly inhabited by multiple clones of his version of Lister, and the ship is filled with their terrible guitar playing and Rastabilly Skank.
Next, Rimmer finds himself in a dimension where he is the ship computer, much like Holly was in his own, and he is simply a head without a body on a monitor. As Kryten approaches down the corridor, Rimmer demands to know why he can't move. Kryten merely wishes him good morning, and squeakily cleans the monitor. The quantum skipper is in the same monitor, and Rimmer manages to push the button with it nose, skipping out of there.
Rimmer then finds himself in yet another dimension, this time he has his body but he is strapped down to the table in the sleeping quarters, which is lit by an eerie red light. His crewmates stand over him wearing dark robes, holding candles and chanting, while Lister goes to stab Rimmer with a knife, apparently in some sort of occult ritual. However, Rimmer is again able to beam out in time.
Rimmer then travels into several different dimensions, where he is seen either clearly disappointed with the result, or is scared and fleeing from some form of unseen danger, and in each case immediately beams out again. Exactly what Rimmer sees or is threatened by in these dimensions is never shown; however, various noises are heard, such as growling, roaring, screeching, elephant trumpets, squelching and machine gun fire. The exterior of Red Dwarf is seen passing through different starscapes as Rimmer skips, and one dimension is seen where Red Dwarf is actually blue instead of red.
Finally, Rimmer ends up in a dimension where Red Dwarf is still in its original design from before the nanobots upgraded it (appearing the same as it did in Series I-V). He is back in White Corridor 159 and wearing his old beige uniform, but realises that the "H" on his forehead is gone - he is human in this reality. A female crewmember, Science Officer Parkinson, walks by him and calls him "Sir". Rimmer runs to a wall monitor and looks up his file - in this reality, he apparently has everything he ever wanted, being a Navigation Officer, and is married with four children, all boys. Parkinson walks back to tell Rimmer that the captain wants to see him, and that she will tell Mrs Rimmer that he will be a few minutes late, and gives the Rimmer Salute as she walks away.
However, when Rimmer walks into the Captain's Office, he is horrified to see that a mustachioed Dave Lister, his old bunkmate and subordinate, is the captain on this ship. Lister explains that he has had a stasis booth installed in the office, so that he can store cold beers or hot freshly cooked food in it, and have them any time he likes. After Rimmer refuses a drink due to it being lunchtime, he tries to explain to Lister that he is from another universe - but Lister believes that he is talking about "The Multiverse" on Venus, a strip club, where Lister met his stripper wife Crystal.
Rimmer asks how Lister came to be captain, and Lister explains that he spotted the faulty drive plate which in Rimmer's dimension had led to the Cadmium II radiation leak that had killed the crew. Lister's diligence averted the disaster in this universe, earning him a significant promotion and beginning his rise through the ranks.
Lister takes Rimmer onto their old Z Shift sleeping quarters (the original bunk room they used in Series I and II), explaining that they not been used in years, and had been kept how they were left. Rimmer looks out over the porthole window to see Earth, a sight he had not seen in three million years. Rimmer contemplates staying in this universe, since he is alive and an officer in this reality, and says that he shouldn't be jealous of Lister, since he is only the captain of a beat up mining ship doing jags up and down the Milky Way every six months.
However, when Lister explains that he refused a settlement from the JMC when he fixed the drive plate, and instead opted for shares. When they discovered a planet rich in Helium-7, he made a fortune from the shares. Rimmer says that, although he has everything he has ever wanted in this universe, he could not stay in a universe where Lister was more successful than him, since it would be too painful. He then skips out for the last time.
Rimmer then finds himself back in own dimension, in his usual bunkroom, where his own versions of Lister, Kryten and Cat are playing poker for matchsticks. Lister quips that infinity clearly wasn't enough to find a dimension where Rimmer is not such a loser, and says that they will deal him into the game. Rimmer smashes the Quantum Skipper to pieces underfoot in frustration. ("Skipper", Series XII)
While Rimmer visits several different alternate realities, only three are shown in depth, with two worlds offering more detailed glimpses and the rest merely shown as Rimmer finds something disturbing or is forced to run away from something terrifying:
- A world from a point just before the radiation leak that killed the crew, forcing Rimmer to 'skip' to another dimension before he is vapourised. Two notable differences being that Rimmer is already a Hologram and that Captain Hollister tried to escape using the escape pod (which jammed) rather than them both being in the Drive Room when the radiation leak hit them.
- 'Rat World', where Lister is more cultured, but the highly evolved animal on the ship is The Rat rather than Cat, and the rest of the Rat race remain on the ship in various other decks
- A world where there are multiple Listers.
- A world where Rimmer is apparently the ship's computer, as he is shown on Holly's monitor.
- A world where Rimmer is the navigation officer with a wife and four sons, and Lister is the captain of the ship, having been bribed with several shares in the company after he reported the radiation leak before it could kill the crew and then received a sizeable bonus after finding a planet rich in Helium-7.
- Since Rimmer had spent three million years dead and not existing before being reactivated as a hologram, when he quantum skips into a dimension where Red Dwarf was not three million years into Deep Space he instead finds himself back in the 22nd century. This is not technically time travel per se presumably because, when Rimmer skips, he skips into the body of a counterpart who is the same chronological age as himself (i.e. having spent thirty years on board Red Dwarf) whether a hologram or alive, and wherever his same age counterpart may be in the space-time continuum.
- The way that Rimmer uses the Quantum Skipper is very similar to the premise of the 1980s TV show Quantum Leap. There is a significant difference in that, in Quantum Leap, the main character jumped into the bodies of random historical figures, and usually resulted in him altering history for the better. However, in this episode of Red Dwarf, Rimmer is jumping into the bodies of other versions of himself in alternate dimensions in his search for a better life for himself.
- Kryten tells Rimmer that the Quantum Skipper device requires some recharging between skips. After Rimmer's first skip, this creates some tension as he realises that the Cadmium II radiation leak is yet to happen on this other version of Red Dwarf. However, the device recharges just in time, and Rimmer is able to skip again into another universe, just before the flames hit him. This would seem to create a continuity error, since in a number of later subsequent skips, the skipper device apparently does not need a recharge time, with Rimmer beaming strait out of realities he doesn't like.
- However, it is possible that the skipper still did require a recharge time, and we simply don't see Rimmer spending any time in those dimensions when it could be implied that he did.
- Alternatively, it is possible that the device had built up and stored enough charge for later skips since Rimmer had spent a significant amount of time in the first and second dimensions he visited.