They say that every journey begins with a single step. Well, mine didn't - it started with a cup of tea in the lobby of the Kuching Holiday Inn. The brew was strong and the murky colour of the river outside. Kuching shuddered under the onslaught of a devilish storm. The heavens were unburdening themselves of a year's worth of rain, and I was fretting about the expedition ahead.

Perhaps all those years in the Crawley branch of the Woodcraft Folk had simply been preparation for this. I was within a whisker of the Equator, preparing to plunge into the Borneo jungle to meet the headhunters - and they would not be the 'executive search' variety.

Since arriving in Kuching, I'd been confronted by a series of puzzles. For example, where was I? I'd booked to go to Borneo, but found myself in Sarawak (which I'd previously assumed was a small African nation). It turns out that Sarawak is a Malaysian state and shares the island of Borneo with an Indonesian province and the oil-rich kingdom of Brunei.

Another mystery: why does the state emblem include a badger? This creature is rare anywhere east of Kent, and completely unknown in Borneo. Its appearance on the coat of arms is a relic of colonial arrogance. For 100 years from the mid-19th century, Sarawak was ruled by the original White Rajah dynasty. The Brooke family had won the state in a piece of Victorian skirmishing, and treated it as a private fiefdom. Tenuous logic - Brooke sounds like Brock, which is associated with the badger - provided an animal, however anomalous, to grace the crest.

I found this out at the Sarawak Museum, a sprawling clutter of cultural heritage and colonial intrigue. The islanders James Brooke subdued were taught an anthem which ends 'Sing loud with joyous sound] God bless the Rajah Brooke'.

After the Second World War, colonies everywhere were striving for independence. But Sarawak's last White Rajah, Vyner Brooke, handed the territorial heirloom back to Britain. Twenty years ago, Sarawak finally shrugged off Imperial domination and joined the Malaysian Federation. The island state remains aloof from the mainland, though, and constitutes a delightful ethnic muddle: Malays and Chinese have settled alongside the indigenous tribes, notably the Iban - with whom I had an appointment.

Besides tracing the colonial history, the museum helped me to prepare for an encounter with the Iban people. It boasts a longhouse display, providing a foretaste of their lifestyle. One exhibit describes in painful detail the Iban tradition of self-mutilation of the penis, involving an inch-long nail (rusty, too, if the example on show is typical). If this is what they do to themselves, what might they do to other people?

The omens were poor. Having been picked up from my pounds 9-a-night 'lodging house' an hour earlier, I was taken to the Holiday Inn and left to sip tea while Peter, the guide, drove around town collecting punters from more opulent establishments. We were heading into the jungle neither on horseback nor by elephant, but in a minibus. Its sturdy windscreen wipers could carve a path through the brutal rain, and a chunky air-conditioning unit tamed the morning humidity.

The head count was an inauspicious 13. A handful of expatriates on leave from Hong Kong and Singapore, a couple of Germans ticking Borneo off their I-Spy list of destinations, a few Australians exploring a geographical near-neighbour, and an Anglo-Belgian family who would chatter easily in English, but revert to a spatter of Flemish when the going got rough.

The first hour witnessed a debate over what we should take to the Iban as presents. The chief collects the equivalent of pounds 2.50 per visitor, but it is customary (and, I thought, bizarre) to bring offerings of cigarettes and biscuits. We had an intra- bus cultural clash over what sort of biscuits; I held out for custard creams, while the Germans wanted something a bit less tasty.

Halfway through the ride I sniffed something odd, a cross between disinfectant and rotting meat. We were approaching Serian, the durian fruit capital of the world. The durian fruit is an olfactory outcast. Everywhere in Sarawak, signs on buses and in shops forbid possession of it. It smells dreadful, but - as I discovered in Serian market - tastes blissful. Imagine a fruit with the size and spikes of a pineapple, whose flesh has the consistency of dough. Twirling it around your fingers, simultaneously trying to hold your nose, you nibble at a delicacy which tastes of all the best things: strawberies, peaches, cream and a hint of port. It has the alleged added advantage of being an aphrodisiac.

Most of the other goods on sale were still moving. Chickens clucked in alarm at the prospect of imminent purchase, while a gallon of sago worms wriggled unhappily in a bucket. Some people eat them raw in the hope of longevity, increased libido and/or a cure for gout. Others prefer them deep-fried. Either way, they cost 5p each.

The bus laboured onwards and upwards towards the glowering grey sky. We spilled out - me clutching my catering pack of custard creams - on the banks of the Skrang river. The vessel that was to bear us upstream looked as if it had escaped from the University Boat Race - long, thin, and thoroughly uncomfortable - but sported an outboard motor.

A wake of exhaust trailed behind this woefully unstable launch, slicing through the tide and taking bends at impossible speeds. I felt like a pillion rider, uncertain which way to lean. Tree roots wrestled down to the waterside. The jungle hung intensely green against the sullen sky, while the incessant whine of the outboard obliterated any sound of the wilderness.

Some of our hosts had climbed down from the longhouse to the riverside to observe our arrival. The Iban face is startlingly vivid, the colour of mahogany, with eyes that sparkle even in the gloom. Yet the resigned expression on more than one of these fine visages read 'Here they are again'. Anyone in search of a community untainted by tourism is too late.

The surroundings looked oddly familiar. I realised the temporary huts at my school were versions of the longhouse. But the Borneo original was raised on 6ft-stilts, rather than stumps; it extended for 200 yards from the riverside into the jungle; and it had no cracked, filthy windows - in fact, no windows at all. When I was at school, the huts were inhabited by a curious mix of trainee young offenders and Woodcraft Folk elves (ideologically sound, but devoid of playground credibility). In contrast, the longhouse was home to 100 Iban people - plus the heads of their enemies.

When you enter the longhouse, the second thing you see is a dozen skulls, dangling in a string bag by the door. But your attention is first caught by the floor-to-ceiling posters advertising Perilly's menthol cigarettes. I breathed a smoky, minty sigh of relief. I'd brought the right brand of fags.

We eyed the occupants, smoking and chatting, with more curiosity than they regarded us. Headhunting is now outlawed in Sarawak, and the victims suspended by the doorway date from decades ago when collecting heads was regarded as the supreme sign of virility. Now, the size of one's outboard motor is the guide to social status.

Peter took us off to inspect our sleeping quarters. The Iban sleep on the floor of their longhouse; tourists get a brand-new dormitory complete with mosquito nets and Western lavatories. Positive luxury, at least by Woodcraft Folk standards. (Later, though, the Anglo- Belgians staged a family snoring competition.)

The theme of adventure for wimps continued with dinner. 'In the evening, a jungle feast awaits,' the brochure had promised. Yet, along with our belongings and biscuits, the guide had hauled upriver several loaves of sliced white bread. We ate jungle-feast sandwiches in the chief's quarters, sitting cross- legged on the floor next to a television inadequately concealed under a teatowel.

Any performance prefixed 'folkloric' in a brochure seems guaranteed to embarrass both the artistes and the audience. The Iban people, once proud overlords of the Skrang river and feared buccaneers, now dispense a dismal approximation of their cultural heritage to a bunch of bored tourists. Geriatric dancers shuffled half-heartedly across the longhouse floor, and were rewarded by cringingly muted applause.

The deafening joy of a tropical dawn put the disquieting night in perspective. The weather had temporarily forgotten it was the middle of the rainy season. A ruby sun struggled free of the horizon, while the beasts of the night hooted with disapproval at the squawking, barking, crowing, oinking din of the longhouse's animals. Such was the CD-quality, wraparound sound that accompanied my blissful early- morning splash in the cool river.

Another round of Mother's Pride sandwiches, and we were taken on a lightning tour of the 'jungle experience', including some inept fishing and a distressing exhibition of cock- fighting. But, like any good tour, the best was left until last. It could have been called 'How to get a head' (or, rather, a corpse). We were to be taught how to shoot poison arrows from a blowpipe, a skill akin to oral darts.

The marksman's skin had been baked to dark copper, but it bore almost Biblical illuminations - bold, nave swirls of colour. The tattooed tutor stuck a palm leaf to a tree 20 yards away. I took the blowpipe, aimed at this target, puffed. The missile spat from the pipe, nearly taking out the entire troupe of Anglo-Belgians (engaged in a particularly frenetic Flemish feud), and pierced the heart of the palm leaf. In the Woodcraft Folk, you got a badge for that sort of thing.

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