By Gemma Pitcher

Throughout the centuries Zanzibar Island (Unguja) and, to a greater extent, Pemba Island have been famous as centres of traditional religion and witchcraft, alongside their better-known role as centres of the spice and slave trades. Today the cult of the shetani (meaning a spirit or spirits, the word is singular or plural) is still going strong in Zanzibar and Pemba – a dark undercurrent unseen and unknown by the majority of visitors.

According to local traditional beliefs, shetani are creatures from another world, living on earth alongside animals and humans, but invisible most of the time and generally ill-intentioned. Many of the ebony carvings on sale in Zanzibar's curio shops depict the various forms a shetani can take – for example, a hunched and hideously twisted old woman, a man-dog hybrid, or a young girl with the legs of a donkey.

There is no real way, say the locals, of protecting yourself from the possibility of being haunted or attacked by a shetani. The best thing is simply to keep out of their way and try to make sure they keep out of yours – for example by hanging a piece of paper, inscribed with special Arabic verses, from the ceiling of the house. Almost every home or shop in Zanzibar has one of these brown, mottled scraps, attached to a roof beam by a piece of cotton.

Should the worst happen in spite of these precautions and a shetani decide to take up residence in your home – or even, in the worst case scenario, your body – the only thing to be done is to visit a mganga (sorcerer). To be a mganga is a trade that generally runs in families, with secrets and charms passed on from father to son or mother to daughter. Waganga (plural of mganga) meet periodically in large numbers to discuss their business (patients must pay handsomely for their services) and initiate new recruits. A committee of elderly, experienced practitioners will vet a younger, untested mganga before declaring him or her fit to practise.

Each mganga is in contact with ten or so shetani, who can be instructed to drive out other shetani from someone who is possessed, or to work their power in favour of the customer. The waganga are also herbalists, preparing healing medicines where spirit possession is not indicated, or combining both physical and occult treatment in severe cases.

But there are some shetani, goes the current thinking, which even a mganga cannot control. The latest and most famous of these was (or is) Popo Bawa – a phenomenon of far greater significance than just a run-of-the-mill shetani, which gripped Zanzibar's population in a wave of mass hysteria in 1995.
Popo Bawa (the name comes from the Swahili words for 'bat' and 'wing') began on the island of Pemba, where he terrorised the local population to such an extent that they called upon their most powerful sorcerers to drive him across the sea to Zanzibar. There the reign of terror of the 'shetani-above-all-shetani' continued.

The experiences of those who claimed to be visited by the demon were terrifying. They awoke in the middle of the night to find themselves paralysed and with the feeling of being suffocated. They then saw a squat, winged figure, around one metre, or slightly smaller, and with a single eye in the middle of its forehead, approaching the bed. Helpless, they were powerless to move or cry out as the demon raped them, men and women alike. Only when Popo Bawa had departed were they able to raise the alarm.

During the height of the Popo Bawa hysteria, people took to the rooftops and village squares, following a rumour that said safety could only be had by those who slept outside, in a group. Despite precautions like these, tales of the demon's progress around the island spread, until the government was forced to broadcast announcements on the radio pleading for calm. Despite this, a helpless, mentally handicapped young man was beaten to death by a mob that had become convinced he was the demon. This seemed to be the climax of the whole affair – after that, the hysteria abated somewhat and Popo Bawa retreated. He is widely expected to return, however, and when local people talk of him, it's with a nervous laugh.

American psychologists came to Zanzibar to study the events and write papers, and stated that the case of Popo Bawa is simply a Zanzibari version of a phenomenon known as a 'waking dream'. One of the characteristics of such a dream is a feeling of being weighted down or even paralysed. Other characteristics include extreme vividness of the dream and bizarre or terrifying content. It is this same phenomenon that is used by sceptics in the USA to explain the stories of those who claim to have been abducted by aliens.

Nevertheless, to the people of Zanzibar, Popo Bawa was very real and proof that shetani exist. Of course, they are not all as horrific as Popo Bawa; the lesser shetani come in all shapes, sizes and colours – beautiful Arabic women, hideous Ethiopian hags, or tall, handsome white men. Shetani can be forced to work for humans, but it's a risky business. Some successful businessmen are said to keep a whole room of shetani in their houses to promote material success and make mischief on their adversaries. But the price of such supernatural intervention is high – a goat, a chicken or a cow must be sacrificed regularly and its blood sprinkled in the four corners of the room. If this sacrifice is not faithfully and regularly made, the shetani will take a terrible substitute – it will demand instead one of its master's male children…