I can’t remember why I put the original Japanese version of Godzilla on my Amazon list — it was a recommendation from either Ramsey Campbell or Mark Kermode — but I’m glad I got to see it. As ever with a cult film like this, you can think you know what it’s about without seeing it, but usually you’re wrong.

For instance, it’s generally accepted that Godzilla’s levelling of Tokyo is all about the bombs dropped on Hiroshima and Nagasaki, but what actually sparked the film off, and what resonates more with the plot, was an incident in March 1954, when the supposedly safe test of a 15-megaton bomb on Bikini Island resulted in a Japanese tuna-fishing boat being showered in radioactive dust (eventually killing one of the crew), as well as having a serious effect on the fishing industry, with whole shoals of fish being found to be highly radioactive. (There’s a contemporary 10-minute documentary about the incident on this BFI DVD.) The Japanese attitude to the bombs dropped during the war was along the lines of “let it stop with us”, and Godzilla is all about the unlooked-for effects of continued experimentation with A- and H-bombs rather than their initial use.

Compared to the US monster movies of the period, Godzilla presents a far darker and more thoughtful exploration of its themes. Of the two scientists in the film, Doctor Yamane (played by Takashi Shimura, direct from finishing Kurosawa’s Seven Samurai) represents the old world of science-for-science’s sake, and although this blinds him to the danger they’re in (he wants the monster to be studied, not killed), Shimura’s acting keeps you sympathetic with the role, as he goes around shellshocked and depressed by, but unable to face, the horror that has been unleashed. The younger Doctor Serizawa, meanwhile, has in his researches discovered how to create an Oxygen Destroyer — the perfect weapon to use against the amphibious Godzilla — but at first hides it away, afraid that once it is known about, it will be used on people next.

Despite Godzilla’s (apparent) death, the film ends on a gloomy note. As pointed out in the interesting commentary, Doctor Yamane’s final remark, that if atomic testing continues there could well be more Godzillas, would be interpreted nowadays as simply leaving the door ajar for a sequel, but at the time was meant seriously as the film’s warning of very real dangers to come should the world continue to play with such powerful but little-understood forces.