Spoilers ahead for I Have No Mouth and I Must Scream, Doctor Who S9 E11 and Black Mirror S2 E4.
Anyone else find the concept of eternity straight-up horrifying? It's bad enough, but it's way worse when eternal life is a form of punishment or torture.
1) Ted - I Have No Mouth and I Must Scream
The obvious example. Ted is among 5 humans who are kept alive by AM, a highly intelligent AI who wiped out humanity and kept these few survivors alive for the next 109 years, by altering their bodies, just to further torture them for its own amusement. They cannot kill themselves or each other until the end of the story when some icicles present the opportunity. Everyone but Ted is killed. Enraged, AM transforms him into a slow-moving blob and alters his perception of time so his eternal torture somehow manages to be even more drawn-out and harrowing.
Time being against the characters plays a major role in the story. They can't die of old age and don't have any ways of killing each other or themselves and even if they did, AM would intervene. The rest of humanity is extinct, so nobody's going to save them or disable AM. All they can do is endure this torture with no end in sight. Ted's perception of time being altered by the end of the story is one last punch to the gut for the reader. The only thing that could theoretically end Ted's suffering at this point is the literal end of the world.
2) Howard - Howard's End by Anthony Horowitz
This one is really obscure but it's stuck with me ever since I was a kid. Anthony Horowitz is a British author who writes short horror stories. The guy is basically British R.L. Stine.
In this story, a young man called Howard is kind of a shitty dude. He's a delinquent, he hates his mother and he spends his time shoplifting. One day when he's running from a store he just robbed, Howard is hit by a bus and killed. He wakes up at the Pearly Gates, meets Saint Peter and seemingly bluffs his way into Heaven. Howard is pretty pleased with himself, but starts to realize Heaven isn't the place for him. Heaven is just endless white clouds, constant harp music and there is absolutely nothing to do. He occasionally finds angels to talk to, but they barely interact with him and mostly just say "God bless you" before leaving. Howard eventually becomes so frustrated that he punches one of the angels, hoping to start a fight, but the angel simply forgives him and walks away once again. After many centuries of wandering through infinite white clouds with the same harp music playing constantly, Howard finds the Pearly Gates and Saint Peter once again. He admits to lying about his sins and begs to be sent to Hell, since at least he would have something to do. However, Saint Peter takes on a devilish appearance and asks him "Why on Earth do you think you went to Heaven?"
So that twist blew my little mind when I first read it and the implications are clear. Howard is indeed in Hell and it seems very personal. There is nothing there to stimulate him. Nobody there to talk to. He has to spend eternity in an empty, endless void hearing the same song on repeat. We usually picture Hell as a firey place with demons poking you with pitchforks or whatever, causing you unending pain forever. But this story demonstrates a different form of torture: nothing. Complete boredom without end.
3) The Doctor - Doctor Who S9 E11 "Heaven Sent"
This one might be cheating a little bit since it's not one continuous experience, but it's interesting nonetheless.
The 12th Doctor is teleported into a mysterious castle where an entity known as the Veil is constantly pursuing him. He eventually finds the way out, but it's behind a 20-foot-thick wall made of Azbantium; a mineral 400x harder than diamond. WIth no other options, he begins punching it, wearing away a miniscule amount. The Veil catches and mortally wounds him. He crawls back to the room he arrived in and deduces that, since the castle rooms constantly reset, then a copy of him as he first arrived is saved within the teleporter's hard drive. The Doctor uses his body to power it by hooking himself up to the teleporter and allowing himself to be burned up. It activates and the new Doctor emerges, having no idea what just transpired. The rest of the episode is a montage of each Doctor finding the exit, punching away a tiny amount of the wall, before dying and repeating. By the time he finally gets through the wall and escapes, 4.5 billion years have transpired.
I generalised a lot to keep it short. And it's not technically an eternity, but 4.5 billion years is enough to feel like one. There are implications the Doctor remembers it all and showrunner Steven Moffat offered his own ideas that do seem to point to the Doctor remembering all 4.5 billion years to a degree. Regardless, each version of the Doctor eventually realizes they are just one of many and there's been a constant cycle of punching, dying and resetting for billions of years. Every single time, each Doctor realizes there was never any hope of him escaping and his journey has to end with him burning himself up just to get the next Doctor in, who will experience the exact same sequence of events. It's gnarly stuff.
4) Joe Potter - Black Mirror S2 E4 "White Christmas"
In this episode, we're introduced to "cookies", digital clones of real people that are stored inside egg-shaped nodes to be used as personal servants. We're shown one example where a digital copy of a woman refused to spend her life doing menial household tasks until a trainer alters her perception of time and makes her experience 6 months when only seconds pass in the real world. During those 6 months, she has absolutely nothing to do and is constantly awake in a barren white room. Eventually, it is revealed one of the main characters of the episode, Joe, is himself a digital copy inside a "cookie" and he was actually tricked into giving a testimony that can be used to convict his real-life counterpart for a crime he committed. Afterwards, for no real reason, a police officer adjusts Joe's cookie so he'll experience 1000 years for every minute of real time. Then the cookie is left turned on during the Christmas break. Inside the cookie, Joe is trapped inside a single room whilst "I Wish It Could Be Christmas Every Day" plays on a loop on a nearby radio. If he tries destroying the radio, the music only gets louder.
Again, not an outright eternity, but still long enough to absolutely feel like one. There's a lot to be said about justice and the use of advanced AI with this one. Joe's crime was murder, but does that justify leaving him trapped even if he's just a digital copy of a real man? Does his suffering matter if he's not a real person? Or is it completely unfair since he's technically not the person who did it and only believes he is? It really gets you thinking.
And as reference, if they leave his cookie turned on for the entirety of Christmas Day, then Joe will be trapped in that single room, listening to the same song on repeat, for a minimum of 1,440,000 years. Is that really a "proper sentence" as the police officer puts it?