Hint: If you're watching a science fiction/fantasy TV show and someone shows up, apparently dead of old age... it's always something else. Prematurely aged stiffs showed up on two different Syfy shows recently, but aging-to-death has been a time-honored trope.
We were spurred to think about this after noticing that recent episodes of Warehouse 13 and Haven both featured withered stiffs, who hadn't started out that way. (Spoilers for both episodes below.)
In the case of Warehouse 13's "Age Before Beauty," the culprit turned out to be Man Ray's camera, which had the power to steal the youth and vitality of fashion models — and which got used on poor Myka.
In the case of Haven's "Ball and Chain" episode, it turned out that the prematurely aged men were all having sex with the same woman, who was somehow leaching the vitality out of them... and then somehow, the men's energy was being turned into babies, born just a day later.
But there's lots of other science fiction shows that feature rapid aging, including...
Babylon 5. We hear early on that the Babylon 4 station disappeared shortly after it became fully operational. But then it turns out (spoiler alert!) that the station was actually stolen in the future, and taken back to the past to fight in the first Shadow War. Because of all these time-travel shenanigans, the rift in that area of space causes rapid aging, among other problems. In "Babylon Squared," the pilot they send out to investigate comes back dead, apparently of natural causes — he's only 30, but his internal organs look like those of a man three times his age. Later, the same rift makes Sinclair age as well, but he manages to survive.
Buffy the Vampire Slayer. This is one of the best-known examples, and includes the classic trope of "old guy has young person's tattoo." In the episode "Anne," Buffy runs away from home and goes to work as a waitress in a diner. But it turns out that young people are going missing in L.A., and then later they're turning up again — old and dead. Buffy discovers they're being sucked into Hell, where everybody ages more quickly. Contains the classic line: "Want to see my impression of Gandhi? Well, you know, if he was really pissed off."
Fringe. This show wasted no time going for both the rapid-aging and super-fast-pregnancy tropes, in its second episode, "The Same Old Story." A woman becomes pregnant for a few minutes, then gives birth to a baby, who ages and dies within half an hour.
Doctor Who. In the classic episode "Blink," the angels zap people back in time, so that they die of old age in the present. Strictly speaking, this isn't rapid aging, since they live a full and happy life first, but it's still the trope of young people suddenly dying of old age. And of course, the Doctor himself almost dies of accelerated aging in "The Leisure Hive" and "The Last Of The Time Lords." And the same fate almost befalls his companion Jo in "The Claws of Axos," not to mention Tegan and Nyssa in "Mawdryn Undead." There's also poor Professor Kerensky in "City Of Death," who thought the alien Jaggaroth needed a lot of chickens.
Star Trek: Phase Two. Lots and lots of people have been faced with rapid aging on Star Trek, including Dr. Pulaski in TNG and Harry Kim in Voyager — but most famously Kirk and his landing party almost age to death in the episode "The Deadly Years." Only Chekov is immune to the rapid-aging sickness... at first, anyway. In the fan-created continuation of the original series, Phase Two, it turns out that Chekov wasn't immune after all — it was just in remission. He starts growing old fast, and this time Dr. McCoy can't do anything about it — and (spoiler alert again!) Chekov actually dies at the end of the episode. The original Chekov, Walter Koenig, returns as the aged Chekov, and original series writer Dorothy C. Fontana wrote the episode. There's also a "special edition" version, where Chekov wakes up to realize it was all a dream.
The X-Files. In the episode "Død Kalm" — which seems to crop up on a lot of people's lists of the show's worst episodes — Mulder and Scully visit a Navy ship in the Norwegian sea where "free radicals" in the water are causing people to age super fast, and some people do age to death. But if you're guessing that Mulder and Scully get miraculously returned to their normal youthful sexual chemistry, then you've probably seen a TV show before.
Supernatural. In the season 5 episode "The Curious Case of Dean Winchester" there's yet another person with a young guy's tattoos, dying of old age. (Hint: Never get a tattoo on a television show, or you're doomed to be a senior citizen before your time.) Sam and Dean investigate and discover there's an evil man-witch (played by Kyle XY's evil sleazestermind, Hal Oszan) who's running a poker game in which you can bet for years instead of money — but the house always wins. And the boneheaded Bobby turns out to have his own agenda.
The 4400. In the season 3 opener "The New World," the young Isabelle ages into womanhood overnight, which often happens to female children on science fiction shows for some reason. Unfortunately, there's a side effect: Lilly also ages rapidly (turning into Tippi Hedren in the process) and then dies at the end of the two parter. (And apparently this was because the actor who played Lilly, Laura Allen, decided to leave the series at the last moment.)
Breathtaker. Not a television show, but this is the comic that we all assumed the Haven episode was going to be based on, before the "babies" thing was thrown in. A gorgeous, uncannily sexy woman sleeps with men and drains them, leaving them all withered.
Indiana Jones and the Last Crusade. Not a television show, but worth mentioning because it gave us this fantastic image (via Comixed):
And then there are all the situations where people almost age to death, but manage to avoid it somehow. Usually this applies to main characters. Like Myka, for example. And these others:
Stargate: SG-1. In the season one episode "Brief Candle," the team lands on a planet where the inhabitants live out "100 blissful days." Everybody assumes this is a metaphor and they party with the natives. Until they discover that the inhabitants are infected with nanobots that age them rapidly, killing them after 100 days. O'Neill gets drugged by a cake (long story) and sleeps with one of the natives — so he's infected with these nanobots and only has about two weeks to live. Until, of course, Carter figures out how to reprogram them.
Thundercats. In the episode "Trouble With Time," there's a special cave called the Cave Of Time and anybody who goes in there will age at super-fast-forwardy speeds until they die. Too bad the Thundercats are running low on the crucial Thundrillium. (Which makes "Unobtanium" sound like a better name for a substance.) Tygra gets stuck in the Cave of Time, and his friends can only hope that Cheetara's super fast speeds will enable her to run into the Cave of Time fast enough to avoid aging to death, so she can rescue him.
Forever Young. Also not a television show, but this movie, written by J.J. Abrams, is worth mentioning. Mel Gibson gets cryogenically frozen in 1939, sort of by accident, for decades, and wakes up in 1992 — "the future." His old sweetheart has grown old and Gibson's character is out of touch with this new-fangled world, which is full of gadgets and all sorts of fangling. Conveniently, he starts aging rapidly towards the end of the world, as if the cryogenic process only delayed the aging process, and by the end of the film, he's an old guy, near death.
Additional reporting by Mary Ratliff. Thanks also to Fuunsaiki, Jerry Conner, Noelle Keyser, Gwendolyn, Becky, Jesse Stringer, Lisa Easthan, Michael O'Brien, Mark Townsend, and Molly Knudsen.