As Red Dwarf continues its endless drift through space, it passes into the orbit of an ocean moon. Aboard, Lister and Rimmer are playing a game of "Mine-opoly", with a personal wager riding on who can win. If Lister can unseat Rimmer, an undefeated champion, from the game, then he gets to have a whole week where he can do anything he wants and Rimmer isn't allowed to complain about it. If Rimmer retains his title as the unbeaten champion, then Lister has to wear an evening gown until he masters the ability to play one of Rimmer's James Last songs on the bagpipes.
Naturally, with stakes like this, Lister cheats, swapping out bad cards for good cards he has concealed under the table. And it sets him up for a winning move, where if Rimmer throws a three, Lister will win.
And then Rimmer proceeds to do just that. Hastily he comes up with an excuse, only to throw another three. And then another. And another. By the time he finally concedes he has lost, Rimmer has thrown an incredible seven threes in a row — the odds of which, he will later learn, are 62 million to one.
Up in the science deck, the Cat joins Kryten as the mechanoid processes the call from a functioning stasis-equipped escape pod. The occupants of the pod contact Red Dwarf, trying to convey a warning, only to be mysteriously cut off in mid sentence. Undeterred, they bring the pod aboard.
Back in Lister and Rimmer's room, Lister is enjoying the first hours of his week without Rimmer badgering him by enjoying a nice icecream cone in bed, before Kryten calls them to the science lab. When they arrive, Kryten tells them about the pod, and shows them the contents: two small piles of dust, which were once Colonel Jim Green and Professor Rachel Barker of the SS. Samsara. Unable to let a mystery rest, and always interested in spiffy new salvage, the team promptly heads to the sunken wreck on the bottom of the ocean moon.
When they get there, things are weird. Skeletons are everywhere, many tangled in the throes of lurid sexual conduct, others apparently killed by more mundane manners. After some scanning, Kryten deduces that everyone was killed by an immense blast of heat that seared them all to solidified bone in one terrible instant, but not how or why. Determined to get to the bottom of this, they press on deeper into the interior.
At least, Kryten and Rimmer do. Lister and Cat are distracted by the presence of a slot machine. To Lister's moral unease, Cat takes a coin from the Orphan's Fund next to the machine in order to play it — and promptly hits the jackpot. To ease his conscience, Lister puts the payoff back in the fund — and the next thing he knows, he trips over and gets some of his dreadlocks caught in the grinding blades of a waste disposer. Cat cuts Lister free, and then ends up getting impaled through the foot with the same knife. Lister patches him up, and then the doors suddenly lock, sealing them both in together, by which point the others are too far away to come and save them. With no other choice, they settle in and prepare to wait for salvation.
Kryten and Rimmer continue on to the flight room, where they find the key piece of the puzzle: the ship is installed with a Karma Drive, a terrifying expansion upon the Justice Field technology they encountered so long ago. Programmed with a designated code of moral behavior, a Karma Drive rewrites reality to function according to karmic behavior, and was an attempt to induce better behavior in crew members. After all, if you did the right thing, your food would taste nicer, the various services would be quicker and more effective, and things would generally go your way. But if you did things that were bad, you would suffer increasing amounts of mishaps and ill-fortune. The problem was, the Karma Drive did not take any sort of lenience into account, and worse still, its moral guidelines were set by programming, which made them very vulnerable to hackers.
But that's almost a minor problem; not only is the ship starting to slide off of its perch into the crush zone of the depths, but the engine is powering up to deliver another lethal heat-flash throughout the ship, the same thing that killed the original crew. Initially, they try to be nice to each other, hoping to use the Karma Drive to deactivate this function, but it turns out to make things worse. When Rimmer gets angry and insults Kryten, though, the engine powers down, which helps provide a vital clue as to what's going on.
Back in the canteen, Lister is going mad as the Cat rambles on with his own inane and inept beliefs about history. He's incredibly relieved when Kryten and Rimmer return... though less so when Kryten proceeds to beat him up. After a few rounds of punching Lister, Kryten sits everyone down and explains the Samsara's history:
Colonel Green and Professor Barker, despite being both married to other people, had been carrying on an adulterous affair for some time, and eventually got themselves assigned to the SS. Samara so they could enjoy a long period in deep space with each other. Of course, the Karma Drive made their lives miserable, attempting to drive them back into proper behavior with a barrage of misfortunes. Finally, the infuriated Professor Barker used her skills to hack the Karma Drive and reverse its programming, so this way it would reward them for continuing their affair. This plunged the SS. Samara into anarchy, and eventually drove them to make one ultimate betrayal so they could escape; they took off in the ship's sole escape pod, even as behind them, the reprogrammed Karma Drive caused an engine flush that killed the entire crew and sent it plunging into the ocean's depths. This then led to their deaths when the Red Dwarf crew came along; woken from stasis in their escape pod, the two immediately went to warn the Red Dwarf of the Karma Drive's presence, which vaporized them for trying to do something so good.
With the ship still slowly sliding into the abyss, the Boyz from the Dwarf decide that now is the time to get out of here, and start making their way back to Starbug. But not before one final twist of karmic irony, when Cat spots one of Lister's Mine-opoly "booster cards" and gives him away as a cheat.
"Samsara" contains examples of:
- Bad is Good and Good is Bad: The reprogrammed Karma Drive works under these rules, punishing good behavior and rewarding bad behavior.
- Chekhov's Gun: The fact that Lister cheats Rimmer, who proceeds to throw an incredibly improbable series of threes that will guarantee Lister's victory, turns out to be a setup ahead of time for the rewired Karma Drive.
- Comedic Sociopathy: Kryten investigates a theory about a computer-screen full of indecipherable gibberish by sitting Lister down in front of it and choking him. Upon reuniting with Lister, he then punches him repeatedly in order to balance out the act of telling him what's going on in this ship.
- Continuity Nod: Reference is made to the events of "Justice", with the Karma Drive that fuels this episode's plot being derived from the same technology as the Justice Field.
- Evolutionary Levels: Invoked and averted, with an incredulous Lister asking why Felis Sapiens would evolve away from the ability to see in the dark, only for Cat to shoot back and ask why Homo Sapiens would evolve away from the ability to brachiate.
- Gone Horribly Right: The Karma Drive technology, as Kryten explains, was far too dangerous to be used successfully. The morality systems were controlled by programming, so anyone with the right skills could hack in and weaponize them as a tool of social control.
- Ignorant of Their Own Ignorance: The Cat displays his absolute lack of knowledge about anything other than being cool whilst locked up with Lister. For example, he's adamant that Archimedes was hit on the head by a bathtub whilst sitting under a tree, which caused him to shout "Formica!" and subsequently invent gravy in his concussed state, for which he was given a special piece of headware to wear to bed in order to cushion his sore skull.
- Killed Mid-Sentence: Colonel Jim Green and Professor Rachel Barker are vaporized mid-sentence by the Karma Drive as they attempt to warn Kryten of its presence and effects.
- Laser-Guided Karma:
- Invoked in the very function of the Karma Drive. Do good things, good things happen to you; do bad things, bad things happen to you.
- Colonel Green and Professor Barker tampered with the Karma Drive so they could continue their affair, and ultimately killed off their entire crew so they could escape it. When awoken by the Red Dwarf millions of years later, their instinctive attempts to warn their rescuers of the danger causes them to be killed by the very technology they tampered with.
- Love Makes You Evil: Colonel Green and Professor Barker are so infatuated with each other that they'd rather tamper with the Karma Drive than simply stop sleeping with each other. Which leads to the death of the entire crew.
- Or, at least, Love Makes You Impatient and Misguided. Had Barker taken more time with the code, she could have just reversed the protocols regarding extra-marital activities while leaving the rest untouched. And she only said it was going to be for one night so either everything went to hell in a hand basket very quickly or the Karma Drive itself interfered with her attempts to reverse her changes (as that would be a benevolent act and, to the reprogrammed KD, worthy of punishment).
- Noodle Incident: 62 million to 1 is apparently the same odds you have of being killed with a tangerine, according to Kryten.
- Saying Sound Effects Out Loud: Because the "Bing Bong" machine is being serviced, Kryten has to shout "Bing Bong!"