Winning the 1968 Hugo Award for best novel isn't the only claim to fame of Robert Zelazny's Lord of Light: it also played a bizarre part in the Iran hostage crisis.

As student revolutionaries stormed the walls of the US embassy in Tehran in November 1979, a handful of staff escaped through a back door. They managed to make their way to the Canadian embassy, but were unable to escape from Iran using their own passports. The Canadians and the CIA eventually came up with a cover to get them out of the country – issuing them with new identities and dressing them up as location scouts working on a science fiction film with a middle-eastern theme. This film was supposedly called Argo, and the CIA developed an elaborate back-story to make it appear real. They set up a production office, took out ads in Variety and bought up already-made set designs and script treatments for a film that neatly fitted into the remit of middle-eastern SF – Lord Of Light.

The attempt to make the actual film had stalled in early production when it emerged that one of the crew had been embezzling most of its budget, but the hostage escape operation it enabled was a resounding success (and earned itself the fond nickname the Canadian Caper). That success seems all the sweeter thanks to the delicious irony that the religious revolutionaries in Iran had been duped using the story of a revolution against religion.

The religion in question in Lord Of Light is Hinduism – or, at least, a version of Hinduism that has been operating on an Earth-like planet with the aim of keeping its population enslaved. Yama, Brahma, Khali and co are actually the crew of a spaceship that crash-landed on the planet thousands of years ago. They have used their advanced technology to provide themselves with weaponry that gives them godlike powers, and to transfer their minds to new bodies when the ones they're occupying wear out. They've kept the rest of the human population (largely made up of the descendants of their old bodies) in a state of medieval ignorance and cowed those who don't immediately do their bidding with the threat that they'll be reincarnated as animals – or not at all.

Not that you'd know any of that if you stopped reading before the halfway point. At first it seems as if the gods really are gods – even though they're all fond of smoking cigarettes and slipping in American slang and western cultural references (generally in the form of groansome puns) to deflate the high epic prose in which Zelazny has chosen to present most of his story. The author only slowly reveals the gods' true nature, and the nature of the struggle against them. Even the central character is a mystery – an enigma summed up, but not fully explained, by the novel's typically slippery first paragraph:

"His followers called him Mahasamamatman and said he was a god. He preferred to drop the Maha- and the -atman, however, and called himself Sam. He never claimed to be a god. But then, he never claimed not to be a god. Circumstances being what they were, neither admission could be of any benefit."

And the complications don't end there. The novel's dozens of characters have a habit of changing name as well as shape. The chapters do not fit into regular chronology. Many episodes only make sense in the light of things that happen later in the book; some never really do. It's nearly impossible to tell whether Sam is serious or joking – or whether Zelazny is, for that matter. Did he really write an entire dramatic episode in which an unfortunate character called Shan is given the body of an epileptic just to enable him to land the pun: "then the fit hit the Shan"? What's with the Christian zombies? Is a long episode in which Sam hacks the planet's oppressive Hinduism with Buddhism a giant mickey-take, another example of the absurdity of religious thought, a touching demonstration of the beauty of true spiritual enlightenment or a heady combination of all three? Is this book profound, or daft – or both?

The obscurity and ambiguity are sometimes irksome but generally add to Lord Of Light's considerable appeal. Reading it is a strange and exhilarating experience. I didn't have much of a clue about what was going on for the first 100 pages, but didn't really mind because I was enjoying the dappy dialogue, eastern-tinged scene-setting and epic battles (there are fight scenes in here as beautifully constructed and carefully brutal as Hemingway's boxing descriptions). From the point of view of six American hostages, it's probably a good job it was never made into a film, but the visual appeal is obvious.

Sometimes the epic prose is heavy and overwrought (there are a lot of flames issuing forth and a few too many ponderous constructions: "They sat in the room called Heartbreak and they drank of the soma, but they were never drunken.") Sometimes, too, the more philosophical passages tend towards the windy. But all that's easily forgiven when enlightenment kicks in and you realise how cleverly Zelazny has been spinning the wheels of his story. This intriguing game of bluff would deserve to be remembered even if it hadn't played such a curiously apt part in the hostage crisis.

Next time: John Brunner, Stand On Zanzibar