MOSCOW—A huge wildfire is burning through contaminated forests and abandoned villages around the entombed nuclear reactor at Chernobyl, and Ukraine’s government has warned about the potential spread of radioactive particles in the smoke that has filled the sky since last week.

“ The fire started right on the paths, where stalkers normally walk. ” — Yaroslav Emelianenko, director of the Chernobyl Tour group

On Monday, rain slowed but did not extinguish the blaze that crept to the heart of the Exclusion Zone around the reactor that exploded in April 1986, killing thousands. At the time Ukraine was part of the Soviet Union, which broke apart five years later. The Chernobyl tragedy was documented and dramatized in ferocious detail last year in an award-winning HBO miniseries viewed around the world.

Hundreds of firefighters are working in the area day and night, trying to contain the fire before it reaches a dump for highly radioactive waste, and the containment structure over the plant, referred to as the sarcophagus. The firefighters reportedly are in urgent need of respirators able to protect them from radioactive particles.

The Ukrainian state agency monitoring radiation levels has reported toxic lithium in the air, but the health minister reportedly says radiation levels are normal. Meanwhile, winds have brought the smoke in the direction of Kyiv, making hundreds of thousands of people under COVID-19 quarantine think twice before opening windows.

As often happens with wildfires, the cause of the blaze is not entirely clear. But in a truly strange twist, many in the region blame people who call themselves "stalkers," inspired by characters in the classic science-fiction novel Roadside Picnic published back in 1972, in the Soviet era, by authors Arkady and Boris Strugatsky.

It's a story of how people on Earth deal with a visit by aliens who seem to have stopped off, paid little attention to the inhabitants, and, like irresponsible picnickers, left a lot of their junk lying around in half a dozen “Zones” on the planet. The aliens’ discarded refuse has enormous potential to change life on the planet, if only humans can figure out what it’s for.

Most of the present-day stalkers are respectful of the Exclusion Zone around Chernobyl and some have even fixed up abandoned apartments in the abandoned town of Pripyat. But there are also criminals, and there are constant conflicts with what had been booming legal tourism in the area before coronavirus lockdowns began March 16.

“They hate us tourist guides and our tourists,” Olena Gnes from Chernobyl Tour told The Daily Beast. “Now, when no tourists can travel to Chernobyl’s zone, the ghost city and the villages around belong to them.”

“The fire started right on the paths, where stalkers normally walk,” said Yaroslav Emelianenko, director of the Chernobyl Tour group, who saw the fire and visited burned villages Sunday, then returned to Kyiv to collect generators, respirators, and other aid for firefighters.

Interviewed over the phone by The Daily Beast as he returned to the zone on Monday, he said: “It’s a huge fire,” but added, “It’s hard to judge about the scale of destruction yet.” Emilianenko has posted several videos of the devastation.

Already afflicted by war and pandemic, Ukraine has many troubles these days. More than 3,000 people have tested positive for COVID-19, including nearly 100 clergymen at the main Orthodox monastery in Kyiv. Several coal factories and mines have had to close. The International Monetary Fund has predicted the economy will shrink by 7.7 percent this year.

The virus is spreading in the eastern Ukrainian territories where Kremlin-backed separatist groups rule the self-proclaimed republics of Donetsk and Luhansk, and the war-ravaged communities in that part of the country are particularly vulnerable. “More than 150 medical centers have been bombed in the area during the war,” says Varvara Pakhomenko, the head of Kyiv’s mission for Geneva Call, an international humanitarian organization.

For Ukrainians and Russians, the Chernobyl wildfires and the stories about stalkers evoke memories of the old Union of Soviet Socialist Republics, the USSR, which fell apart in 1991 partly because of the scandalous impact of the Chernobyl nuclear disaster.

The authors wrote about alien civilizations to describe the totalitarian reality in the 1970s. Soviet readers were good at understanding metaphorical language, and easily gleaned meanings between the lines.

The epigraph for the novel is unmistakably political, drawn from Robert Penn Warren’s chronicle of cynical power, All the King’s Men: “Goodness…. You got to make it out of badness… Because there isn’t anything else to make it out of.”

The word “stalker” itself, pronounced stullker in Russian, was imported from English by way of Rudyard Kipling’s novel Stalky & Co., about reckless but chivalrous boys in an English school. The word and the kind of person it might represent grew even more well-known when Andrei Tarkovsky adapted Roadside Picnic for his ominous 1979 movie and called it Stalker.

The book’s central character, Red Schuhart, is a stalker who breaks into a forbidden Zone enchanted by a mysterious force. The slang word for Soviet penal colonies, “zone,” became popular in 1930 when thousands of political prisoners ended up in the same forced-labor camps with criminals. The Strugatsky brothers turned their “zone” in Roadside Picnic into a forbidden place that became a magnet for romantics: “Industrial landscape, in short. Only there are no people. Neither alive ones, nor dead.”

There are six of these “visited zones” on their fictional Earth in a narrative set 13 years after the aliens came and went. There is high security on the perimeter of the zones, and one can enter only with a special pass. But the impetuous stalkers know how to sneak in, find alien objects, and sell them on the black market.

The somber futuristic novel was written 16 years before the Chernobyl catastrophe, but in retrospect seemed to predict not only Ukraine’s Exclusion Zone (sometimes translated as Alienation Zone). So perhaps it was inevitable that self-styled “explorers” in the stalker mode would sneak through holes in the fences around the abandoned town of Pripyat looking for a place with no people, alive or dead.

In Tarkovsky’s movie, the Zone was surrounded with barbed wire, full of rusting train tracks, half-ruined houses, bent and broken lamp poles. The main character, the stalker Red, is addicted to the place.

Today thousands of adventurous stalker fans explore abandoned factories and industrial sites in godforsaken corners of post-Soviet countries, but the Chernobyl zone is something special.

In the Strugatskys’ book, the stalker throws himself into the epicenter of the Zone, into a sphere that apparently is able to make one wish come true, but instead of asking for his own sacred dream, he cries out, “HAPPINESS, FREE, FOR EVERYONE, AND LET NO ONE BE FORGOTTEN.”

Whatever the craziness of the cultists, that hopeful message from the original novel endures, even in today’s troubled Ukraine.

Christopher Dickey also contributed to this article.