The SENS Research Foundation is located in Suite J of an unremarkable office park, in an unremarkable part of Mountain View, next to the unremarkable facade of the Kingdom Hall of Jehovah’s Witness. I know this because, one day in October, I drive right past the office park without realizing, then wander around the building on foot, looking for its equally unremarkable entrance. It’s worth it though, because behind a plain glass door is a man who wants to defeat death.

Aubrey de Grey, chief science officer of SENS (short for the very catchy Strategies for Engineered Negligible Senescence), is waiting for me when I arrive, in jeans and a navy sweater, with a thicket of a beard so long it would make Gandalf jealous. His desk is piled high with papers and books, leaving the room’s two bookcases partially empty. A bike leans against one wall. There are no foosball tables, no nap pods, no open-office concept—no indication that we are located in the heart of Silicon Valley, just a short drive from the offices of Google and Mozilla.

De Grey’s office is my first stop in my journey into the strange and surprisingly overlapping worlds of cryptocurrency and life-extension. But De Grey is not like most tech entrepreneurs, nor is he like most longevity researchers. He doesn’t buy into the health fads popular amongst his peers, like calorie restriction. (“I have the right genes for beer,” says de Grey in the 2007 documentary Do You Want to Live Forever? “And drinking beer in the morning does me no harm at all.”) He’s not hoarding the blood of spritely teenagers (though tech billionaire Peter Thiel, who may or may not be interested in youthful blood infusions, is a SENS donor). And, while he says that cryonics—in which bodies are preserved at low temperatures—is “an extremely valuable and neglected area of medicine,” the whole freezing-and-thawing process is not where his still-beating heart lies.

De Grey’s plan is more ambitious than resurrection: He wants to reverse aging all together. As he outlines in his 2007 book Ending Aging, his strategy is to discover therapies that address the “diseases and disabilities of aging.” Whereas most biogerontologists focus on the complex metabolic processes that cause aging damage, de Grey argues that the focus should be on the seven forms of damage themselves—like nuclear mutations, or the intracellular “junk” that forms as we get older. In short: Focus on treating the symptoms of aging, not their underlying causes.

Though he has plenty of critics, de Grey’s bold approach has also garnered him scores of devoted fans, to whom he dispenses regular lectures and AMAs, and who believe he’s drawing a map that points toward the literal Holy Grail: never-ending life (or at least a much longer and more productive life, until a car crash or something else takes you out).

As he sits stroking his Rip Van Winkle-worthy beard, it’s easy to see how de Grey’s achieved this “kind of a spiritual leader-status,” as he calls it. He dives easily into intricate explanations of two research projects unfolding in the lab down the hall, eagerly describing how one studies mitochondrial mutations, which are thought to cause an increase in oxidative stress. The other looks at atherosclerosis, the narrowing and hardening of artery walls. If we understood more about this buildup, the logic goes, we could better clean it up before too much damage is done.

Though he attends lab meetings and oversees the SENS’s research, his primary task is convincing the general public that death is, in fact, bad and that we should be doing everything we can to stop it. This focus on messaging suits him just fine. “I’m not in this to do science for the sake of doing science,” he says. “I’m in it for the ultimate goal.” He does a “ridiculous” amount of media, he says, and gives around 50 talks a year, from Vietnam to the Czech Republic.

Back in April, at a San Francisco blockchain conference called Block 2 the Future, de Grey began his talk with a disclaimer: “I probably ought to start by emphasizing that I don’t know fuck-all about cryptocurrencies. I am really only here because I have apparently quite a significant fan base in this community, and I am delighted that I do.”

He was referring to the intertwining relationship between blockchain enthusiasts and life-extension advocates, which can feel less like a Venn diagram and more like overlapping circles. There’s a history of members of the blockchain community donating to life-extension efforts. Billionaire and cryptocurrency investor Michael Novogratz donated to the organization that predated SENS in the early 2000s, and the number of cryptocurrency donors has increased exponentially since. In the past year or so, SENS has received more than $6.5 million in cryptocurrency donations, including $2.4 million from Ethereum cofounder Vitalik Buterin last December.

Pine, the anonymous individual behind the Pineapple Fund who donated $55 million worth of bitcoin to various charities last year, gave 2 million of those dollars to SENS. A few other anonymous crypto donors gave around $1 million each, says de Grey. And other cryptocurrency heavy-hitters have long-term involvements with SENS, too. Barry Silbert, founder and CEO of Digital Currency Group, is an investor in one of SENS’s for-profit spin-offs, Arigos, which focuses on cryopreservation of human organs. (Since SENS is a nonprofit and is not permitted to engage in financial speculation, de Grey says the cryptocurrency donations were immediately converted to dollars.)

De Grey believes that crypto’s philanthropic donors skew younger, like with Buterin, just 24, who became a fan after reading Ending Aging as a teenager. De Grey likes to call this new generation of donors “Children of the Revolution,”—and he’s called out older people for not doing their part. “It’s a huge embarrassment,” he told the audience back in April, “to the kind of wealthy individuals of my age, like Peter Thiel or Jeff Bezos or the Google Twins or whatever, who are ostensibly really supportive of all of this, but who have put very small, if any, proportions of their net worth into supporting it. Peter … is a shining example of someone who has put some money in—but let’s face it, he could have put more in.”

Despite knowing “fuck-all” about cryptocurrencies and abhorring cell phones—he calls them the “abomination of the century”—de Grey is not exactly a luddite. He started out in artificial intelligence research before switching, in his late twenties, to biology, a field where he said “there were not enough thinkers” chasing the biggest ideas. He’s come to enjoy his warm welcome at blockchain conferences, where attendees cheer on wildly ambitious, if unproven, ideas all the time. “What I don’t get much of at crypto conferences is the kinds of questions that I get ad nauseum at most conferences: Oh God, where will we put all the people? How will we pay all the pensions?”

Blockchain’s big-picture dreamers have never let tedious practicalities get in the way of their big ideas about reinventing traditional systems of finance, society, and governance. So why should petty logistics stand in the way of eternal life?

The core of the blockchain community is, essentially, composed of thinkers who’ve set their sights on using code to hack our lives for the better. But the desire to hack death has a long history, too. Throughout history and myth, desperate mortals and egotistic demigods have quested for immortality: Gilgamesh tried to stay awake for a week straight in return for eternal life. The mother of Achilles dipped him in the River Styx in an attempt to make him invincible. Whether seeking the Fountain of Youth, the Holy Grail, a vampire’s bite, or a better plastic surgeon, generations have chased the dream of eternal life. In more recent years, sci-fi has been populated by crazed visionaries who see death as a hacker might: a programming error, a bug to be fixed.

In parallel, the allure of suspended animation, which might prolong a life through science or magic, has endured—from Snow White to 2001: A Space Oddity to Marvel’s Captain America. It wasn’t until the 1960s that technologists attempted to bridge the gap between myth and reality through cryonics, the practice of freezing a body with the hope of reviving it in the future, when we have the cure for what ails it. In 1967, Bob Nelson, a former TV repairman who never graduated from high school, became the field’s first trailblazer, freezing “cryonaut” Dr. James H. Bedford shortly after his death.

It was a DIY endeavor. Nelson kept Bedford crammed in a styrofoam box stored in the Los Angeles garage of some friends while final preparations on a cryonics capsule were being made. Nevertheless, Bedford is still frozen today, which could make this first amateur attempt a success—at least if Bedford’s body hasn’t been irreparably damaged by the procedure, if science progresses far enough to reanimate a frozen human, and if he can be cured of the cancer that killed him in the first place.

Not all of Nelson’s corpses were so lucky. The families of many of Nelson’s early cryonics patients sued him after it became clear that, short of funding, he had allowed their loved ones to decompose. After the relatives won a judgement of $800,000, Nelson mostly disappeared, resurfacing in 2014 to publish a book called Freezing People Is (Not) Easy.

Though the process has evolved, 50 years after cryonics’ first freeze, very few cryonicists would disagree with the title of Nelson’s book. Bedford is now one of the 162 “patients” at Alcor Life Extension Foundation, perhaps the most well-known cryonics organization. As of September, an additional 1,200-plus people had completed the legal and financial arrangements required for Alcor to someday pump their body with SuperCool X-1000 Ice Blocker (which limits the number of ice crystals that form and damage cells) and store them at -196°C in a massive stainless steel Thermos called a Bigfoot Dewar. As time goes on, more and more members of the blockchain community might be joining their ranks.

Computer scientist Ralph Merkle, a pioneer in both cryonics and cryptography, says Alcor clients tend to be people with advanced degrees (often in technology) and/or libertarians. “I’m not sure why that is,” he says, when I Skype with him from his home office in Cupertino, Calif. Merkle says he got interested in cryonics after completing several major life milestones, including getting married, completing his PhD, and buying a house. “I was doing my usual planning for the future,” he tells me. “Things go along, wonderfully and marvelously, and then I drop dead. I raised the obvious question, which is, ‘Gee, is there anything that can be done?’ That doesn’t seem like an optimal outcome.”

With his white hair and big aviator frames, Merkle exudes the joking confidence of someone well-established in his field—or, in Merkle’s case, fields. He’s a longtime member of Alcor’s board of directors and is well-known in blockchain as the co-inventor of public-key cryptography. Merkle also bears the distinction of being one of the 10 people referenced in pseudonymous bitcoin creator Satoshi Nakamoto’s 2008 white paper, making him something of a blockchain celebrity.

Like de Grey, Merkle has found cryptocurrency entrepreneurs to be willing donors as he raises funds for Alcor’s cryonics research. “That makes us very happy,” he says. “Obviously, donations are good in general, and if those donations are accompanied by a clear rationale that is associated with a group that thinks cryonics is a good thing, why, that’s also a good thing.”

Earlier this year, investor Brad Armstrong gifted $5 million worth of cryptocurrency to Alcor for a research fund in honor of Hal Finney, a cryptographer and one of bitcoin’s earliest adoptees, who was diagnosed with ALS in 2009. An ardent futurist, Finney arranged to have his body cryopreserved by Alcor after his death. Like a number of their peers, Merkle and Finney shared deep interest in both cryptography and cryonics. But their connection goes deeper. Their audacious techno-utopianism can be traced back to an astoundingly optimistic group founded in the 1990s called the Extropians. The group was cofounded by current Alcor CEO Max More, an early cryonics obsessive so committed to living forever he kept a heart-lung resuscitator in his college dorm room in case of emergency. A true believer in the cryonics cause, More wrote to his Extropian brother Finney, on the day of his passing: “Hal, I know I speak for many when I say that I look forward to speaking to you again sometime in the future and to throwing a party in honor of your revival.”

The basic philosophical idea behind the Extropians was “to fight entropy—the natural tendency of things to run down, degenerate, and die out—with its polar opposite, ‘extropy,’” wrote Ed Regis for Wired magazine in 1994. He seems to have drunk a Holy Grail-ful of their Kool-Aid: “For the first time in history, science and technology have caught up to the wildest of human aspirations and hopes. No ambition, however extravagant, no fantasy, however outlandish, can any longer be dismissed as crazy or impossible.”

Almost 25 years later, most of the Extropians’ dreams—of immortality, of societies free from State imposition, of full control over our biology through the miracle of molecular engineering—are still tantalizingly out of reach. But some are closer—and, if you believe the hype, blockchains might help get us closer.

The Extopian’s techno-utopianism can be seen in those passionate about cryptocurrencies and life-extension research today. “In the next 20 years, if the politicians don’t muck it up, and if AI continues to grow the way we’re predicting it will, we are going to be living in a radically different world,” one user on the r/longevity subreddit wrote me. “I am chasing that experience. That’s why I’m into crypto (because it’s one of these futuristic experiences) and that’s why I’m into longevity (because it can generate more of these experiences).”

Blockchain’s true believers, the ones in it for more than a quick 10X, are seeking nothing short of revolutionary ways to disrupt life as we know it. For many of them, it seems the search for eternal life is just a part of the utopian project. After all, if you believe passionately in tech’s ability to transform our most fundamental financial structures, the leap to hacking our biological clocks seems more manageable. Why shouldn’t you be able to send your money privately to whomever you like, whenever you like? Why shouldn’t you edit human embryos with CRISPR? Why shouldn’t we reinvent the financial system? Why should we have to die if we don’t want to?

Cryptocurrency enthusiast Mark Katakowski is the president and CEO of Forever Labs, which banks stem cells for people to later use in aging therapies. He says there’s a “type of mind” common to cryptocurrency and longevity enthusiasts that doesn’t focus on the short-term horizon, but thinks about big-picture transformational change. “If they see a new technology, they tend to extrapolate,” he says of those with a crypto-cryo mindset. “You can see where it’s all going to go, and that’s why people get so excited.”

Today, the most convincing criticism of cryonics and longevity research is simply that it doesn’t work yet. Nobody’s ever been successfully thawed out. And nobody has ever not died. Critics say that cryonics is nothing more than what it has always been: a sci-fi fantasy at best, or, at worst, a con that preys on the scared and gullible. “Reanimation or simulation is an abjectly false hope that is beyond the promise of technology and is certainly impossible with the frozen, dead tissue offered by the ‘cryonics’ industry,” writes neuroscientist Michael Hendricks in the MIT Technology Review.

In 2006, the Technology Review also organized a competition that invited scientists to disprove de Grey’s “maintenance-based” anti-aging theories, offering a $20,000 prize bounty. Competitors called his theories “vague in the extreme” and “completely consistent with pseudoscience,” but the judges ultimately decided that no one had sufficiently disproven his ambitious venture, and de Grey maintained his bragging rights.

Despite criticism, brash technologists have never shied away from attempting the seemingly impossible. No one said solving death would be easy. Even figuring out when a person is actually deadhas been hard. Romans would yell the name of the (theoretically) diseased three times in a last-ditch attempt to rouse them before burial. In the 18th and 19th centuries, people were so concerned about being buried alive, that “safety coffins” became popular. These intricately designed contraptions often included a bell that an interred person could ring if they woke up six feet under. It wasn’t until the 1960s that a committee at Harvard Medical School developed a criteria for today’s widely accepted definition of true death: “irreversible coma,” or brain death. In short, as medical technology has evolved, where people draw the line between “living” and “dead” has changed. From if they’re not breathing, to if their heart is not beating, to if an electric shock cannot restart their heart.

Cryonics complicates this more-than-existential query further. If a person declared dead in the 1800s was be revivable with today’s medical technology, is that person really dead? (There’s a reason cryonicists generally use the term “patient,” rather than “body” or “corpse.”) Merkle frames it this way: “The question becomes: ‘Is there a definition of death that is independent of the technology?’”

Anticipating the arrival of workable life-extension and reanimation, and cures for diseases like ALS and cancer, Merkle suggests a new definition of death: “information-theoretic death,” which he defines as the point at which a brain is so damaged that no current or future technology can restore it to its original, healthy state. “That’s something that people who deal with computers and cryptocurrencies and bits understand in an intuitive sense,” he says. In this line of thinking, there may be a distinction between—just plain-old dead, and information-theoretic dead—the former being a candidate for eventual revival.

“I can sympathize with the physicians who say, ‘Look, this is an intricate machine and if you disrupt it by this process of cryopreservation, how can you expect to warm it up and have it work?’” says Merkle. “Of course, the answer is, we don’t.”

Currently, cryoprotectants only do so much to reduce tissue damage caused by ice crystals, which cause cellular damage. A successful procedure would need to repair the damage caused by preservation before even getting to the main problem: whatever caused the person to die in the first place. Merkle and Alcor are placing bets on nanotechnology, and hoping they can keep bodies frozen long enough until it arrives. “Molecular nanotechnology is the most compelling approach ever put forward for comprehensive repair of cryopreservation injury with maximum retention of original biological information,” writes the Alcor Scientific Advisory Board and the Alcor Board of Directors.

In some sense, Merkle sees the problem of life and death as cryptographic. If life is locked up in a mostly dead body, it’s just a puzzle (albeit a complicated one) that needs to be decrypted. “When we freeze someone, there is random thermal agitation and thermal noise that comes from the rest of the world: this source of random information is not available to the ‘cryptanalyst’ trying to ‘decipher’ your frozen body (the ‘encrypted message’),” he writes in his paper “Cryonics, Cryptography, and Maximum Likelihood Estimation.” “It would seem prudent to exercise caution in claiming that freezing, ischemic injury or cryoprotectant injury result in information theoretic death (and hence that cryonics won’t work).”

For now, the cryonic plan is virtually the same as it was in Bob Nelson’s friend’s 1967 garage: Freeze bodies as long as it takes, until technology advances far enough to reanimate them.

“My hope is that when I’m frozen it’s through a technology that’s not hard to undo, so [future generations] won’t have to try really hard,” says economist and Alcor member Robin Hanson. “If they have to try really hard, they probably won’t.”

Hanson is credited with creating the first prediction market and now consults for blockchain prediction market projects Augur and Gnosis. (Slate also dubbed him “America’s creepiest economist” for his controversial views on incels.) After a blockchain company reached out, he proposed a prize system to incentivize cryo-revivals, so that the frozen don’t just remain on ice. “I tried to work out what I thought would be a system,” he told me. But, as he admits on his blog, “Problems remain, such as of kickbacks, theft, fake revival, and mind control.”

For now, the business of life extension is still a business—even nonprofits like Alcor and SENS need to fund their research. Despite the techno-spiritual affinity, the main reason life-extension proponents are regulars on the blockchain circuit is economic: They’re chasing crypto’s money.

On this sunny fall morning, across the street from the runway at the Santa Monica airport, the breezy, hangar-like Museum of Flying is the setting for a blockchain conference called Block Con. Host Kurt Kumar, who also runs Block Con, and the Los Angeles Blockchain meetup, steps on stage, phone in hand, to introduce a panel called “Solving Immortality.”

“How many of you want to live forever?” he asks the audience. “Hands up.”

Someone whooos faintly. “One, two, and the cameraman there. Three, four,” he counts. Another 150 or so audience members remain unmoved. “Okay, so the rest of you don’t care?”

Despite the tepid response, Kumar eventually invites the panelists onstage. Alcor’s Merkle, Forever Labs CEO Katakowski, and SENS Global Outreach Coordinator Maria Entraigues take their places in a row of Boeing airline seats onstage. In short order, Katakowski compares the human body to a Model T, explaining that preventative maintenance is essential to preserving both. Merkle points out that going to the moon in the 1940s seemed like the stuff of science fiction. Entraigues assures the crowd that immortality will not happen overnight. “Everybody will have the option, just like you have the option today if you have cancer to go and get treated or not, which is a type of life-extension,” she says.

Though Katakowski tells me later he thinks the panel went well, it’s clear that not everyone leaves a convert. The next talk starts quickly and I step outside into the Santa Monica sunshine, near the gray and blue Douglas Commercial plane that stands sentinel on the lawn. I suppose it’s no surprise that panels like “Token Economics and How To Legally Print Your Own $$$” are hotter tickets. Immortality is an abstract concept compared to such pragmatic concerns.

For Merkle and de Grey and Buterin and Finney, though, death is not some distant inevitability. It’s a looming threat, an underpublicized global disaster. De Grey calls apathy in the face of such an enemy “the pro-aging trance,” which he defines as “the impulsion to leap to embarrassingly unjustified conclusions in order to put the horror of aging out of one’s mind.”

However you feel about efforts to extend the human lifespan, it’s the sort of topic that quickly veers into the abstract: either a titillating oddity (People freezing their heads! Didn’t Disney do that?) or an academic debate over resources (Should we help certain individuals live to 1,000, or help the millions who don’t make it to 50?). Either way, it’s mostly theoretical.

A few weeks after the conference I speak to Fran, Hal Finney’s widow, who still lives in California. “Hal was a futurist and he really wanted to be around to see the future,” says Fran. “Hal was very strongly an atheist, so he didn’t have any spiritual feeling that he would come back. Cryonics, at least in theory, was an opportunity to someday experience that future.”

It’s easy to focus on the snake oil salesmen, the science, the ethical dilemmas. But for Fran and Hal, there was nothing distant or hypothetical about the endeavor. It might not work they knew, but, what if it did?

“I miss him,” says Fran with a rueful laugh. “He’s a big part of why I am signed up for Alcor, because if I didn’t have a hope that someday he would come back and I could be with him, I don’t know. I’d have to rethink everything. He was a wonderful part of my life.”

Main image by Daniel Chen/Unsplash.