The accident at a nuclear fuel factory in Japan was considered a relatively minor event, and the product of human error. But some observers, including PNS commentator Yoichi Clark Shimatsu, think there is legitimate reason to consider the possibility that the terrorist group Aum Shinrikyo is involved. Shimatsu is a former editor of the English-language Japan Times Weekly in Tokyo.

Japan's worst-ever nuclear accident is universally attributed to human error. Workers at the Tokaimura reprocessing facility poured too much uranium into a chemical mixing tank. But some observers in Japan -- myself included -- have not ruled out the possibility that the incident was the result of a terrorist act.

This was, after all, the second major accident blamed on human error at Tokaimura in less than three years. In March 1997, flaming barrels of nuclear waste led to the airborne release of nuclear material that drifted over Tokyo -- a story that went largely unreported by either the Japanese or the foreign media.

Granted, Tokaimura workers may be sloppier than the average Japanese worker, even after a management shakeup following the 1997 incident, but they are highly skilled, highly paid, and have a personal stake in their own survival. Another possibility that should not be discounted arises from a mysterious letter sent to a Japanese magazine in late 1995 by the underground Vajryana wing of the Aum Shinrikyo, the sect accused of releasing poison gas in the Tokyo subways earlier that year.

The staff of Takarajima 30 asked me to help decipher the coded message. At the time, I was the editor of the only publication in Japan other than Takarajima that was seriously investigating the Aum sect's links to Japan's top politicians, bureaucrats and scientists.

The message, in English on two legal-size pages, was embedded in a passage of literary criticism. The note was signed Shigekuni Honda, the name of a character in "The Sea of Fertility," four novels by Yukio Mishima, who committed suicide immediately after the series was completed

The letter was a rebuttal to an essay by Susan Sontag in which she claims the sci-fi film genre is based on a fascination with catastrophe in the age of the bomb. Instead, this critic asserted, science fiction is really about surviving catastrophe, and is therefore optimistic -- and the key to the genre is the longing for a sense of scientific community resembling the craft guilds of the past.

A professor of American literature at one of Tokyo's top universities, a specialist in science fiction, he immediately recognized the passage as the work of literary critic Frederic Jameson. It was obviously selected as a defense of the Aum sect's effort to build a community of scientists modeled after Isaac Asimov's "Foundation" series.

The ultimate purpose of the guild, said the sect's science minister Hideo Murai, before he was murdered by a Korean gangster, is to rebuild civilization after a cataclysm and to combat the powerful globalist institutions that are bringing on an apocalypse.

The Takarajima editorial staff cracked the code, and I felt a chill as the deciphered message rolled across the screen. "If the Japanese government approves an anti-subversion law, there will be an attack against the Tokaimura reprocessing plant. A second attack will be launched in Southeast Asia."

Soon after the story was published, the magazine Takarajima 30 was shut down -- with no satisfactory reasons given.

Now, a week before the second anniversary of the Tokyo subway gassing, as prosecutors seek the death penalty for the sect's guru, a fire breaks out in Tokaimura.

This summer, the Japanese government launched an all-out assault against the sect, unleashing widespread electronic eavesdropping, making arbitrary arrests and proposing a legal ban. Were the coded threat and the subsequent nuclear incidents merely coincidental?

Another clue is contained in Asimov's masterpiece. After the visible First Foundation was crushed by the Galactic Empire, the invisible Second Foundation persisted to eventually win the universal struggle.

A Japanese reporter who had extensively investigated one of the sect's top scientists from Ibaragi, where Tokaimura is located, has told me that Aum enjoys a huge following within Japan's nuclear establishment, which is riddled with believers from millennialist sects. Canada's main utility company was similarly penetrated by the Solar Temple sect.

Japan's nuclear authority has rigorously prevented left-leaning scientists and laborers from working inside power plants, but they apparently overlooked the greater danger within.