High Speed 2 was supposed to be the future of British transport, a modern, gleaming train line that would shoot passengers from the North down to London, where they could continue on to the Continent with a swiftness that would boggle the mind.

Nevertheless, HS2 has been bedeviled by setbacks. A memorial service had to be held for the 60,000 human bodies that were exhumed along the line. Ominous medieval markings were found along the route in Buckinghamshire, apparently designed to protect the area from evil spirits. The track had to painstakingly weave itself up the country to avoid any buildings of exceptional historical importance.

The overall cost for the 343-mile line has likely doubled since it was first announced, and by completion it is likely to cost the taxpayer $428 million per mile. The coronavirus has obliterated train travel and crippled Eurostar almost to the point of collapse. And, as Brexit proved, it isn’t as if many Brits are longing to align themselves with mainland Europe anyway.

However, last month, the HS2 story started to get really interesting, and the culprit is a tunnel named Kelvin. This might take a little explaining.

HS2 initially estimated that it would take more than 100 years to repay the “carbon debt” from the construction of this high-speed railway.

In September, a group of campaigners set up a ramshackle “Tree Protection Camp” in Euston Square Gardens, a drab patch of grass that is set to become a temporary taxi queue outside HS2’s London terminus. Its aim was ostensibly to build a fort to protest HS2. But, at the end of January, a secondary objective was discovered when the group revealed that some of its members had also barricaded themselves inside Kelvin, a hand-dug honeycomb of tunnels beneath the gardens. The campaigners describe HS2 as the “most expensive, wasteful and destructive project in UK history” and claim that it will irreparably harm the climate.

Tunneling has been a form of protest in the U.K. for several decades, with eco-warriors digging themselves into the ground to resist everything from highways to fracking operations. Inspired by the North Vietnamese tunnels at Củ Chi, the protesters largely follow suggestions laid out by a figure called “Disco Dave” in his Tunnelling Guide: a manual that explains how to dig, ventilate, and encase yourself within a protest tunnel. Why? Because removing protesters from a tunnel is slow, expensive, and extremely high-profile.

Ominous medieval markings were found along the route in Buckinghamshire, designed to protect the area from evil spirits.

Just look at “Swampy.” In 1996, after barricading himself beneath the Devon hamlet of Fairmile for a week to try to stop an extension of a road that runs from London to Land’s End, the baby-faced 23-year-old protester became the public face of eco-warriors everywhere. After his eventual removal from the tunnel, Swampy (real name Daniel Hooper) found himself swept up in the brief Cool Britannia fad of the mid-1990s, appearing on a comedy-panel show and being satirized in a Judge Dredd comic. To top off the circus, the magistrate who passed sentence on him happened to be the mother of future prime minister David Cameron.

After three weeks underground, Rory Hooper, 16, came out of the network of tunnels at Euston and was put on a stretcher.

Swampy mostly disappeared from sight years ago, but he remained a household name in Britain. When, inevitably, he turned up, squirreled deep in the Euston tunnel with his 16-year-old son, Rory, there was a sense of jubilant homecoming. And Swampy, now 47, couldn’t be prouder of his offspring. “He is already becoming a better climber than me so yes, he will probably become better at digging and tunnel dwelling than me,” he explained to The Guardian. “But don’t tell him that, I don’t want him getting a big head.”

This isn’t to say that Rory automatically gets to be the new Swampy. That title is likely to go to the Sandford siblings, Lazer and Blue, who have become the public faces of the protest. Lazer, 20, was arrested last week after a 25-hour operation to remove him from the underground device he had locked himself into, along with his 18-year-old sister, Blue (dubbed one of “Britain’s Greta Thunbergs” by the press). Blue has been busy documenting life in the tunnel on her Instagram account.

The campaigners describe HS2 as the “most expensive, wasteful and destructive project in UK history.”

What makes the Sandfords noteworthy isn’t their strange names or social-media savvy but their aristocratic family lineage. Their father, Roc, is the millionaire landowner of a tiny off-grid Hebridean island named Gometra. He is the son of author Nell Dunn, whose grandfather was James St. Clair-Erskine, fifth Earl of Rosslyn, a notorious gambler.

Inside the tunnel, Lazer locked himself to a complex steel-and-concrete device, which the activists underground referred to as “a concrete cake.”

Meanwhile, Lazer and Blue’s sister, Savannah, also a green campaigner, is arguably best known for stripping in the House of Commons during a Brexit debate on April Fool’s Day 2019. Their upper-class credentials have been underscored by their diet under the tunnels. While Swampy spent his time underground in 1996 nibbling on biscuits, these protesters, according to a report last week in the Evening Standard, have been living off the much more upmarket combo of “posh cheese” and olives.

Lazer was relatively quick to leave the tunnel, departing after 12 days, but Blue and a clutch of other protesters remain underground. And despite everything—rain and snow and collapsing tunnels, and the government operation to quell the HS2 protests across the country ballooning to $67 million—there is a sense that these people aren’t going anywhere fast. Indeed, a brand-new tunnel was revealed last week, two miles north of the Euston protest. It looks like, as long as HS2 is on the agenda, the tunnels are here to stay. That said, none of them are going to have a better name than Kelvin.

Stuart Heritage is a Kent, U.K.–based Writer at Large for AIR MAIL