Shetani have been in Zanzibar forever. They predate any of the foreign powers who, in successive centuries, sailed into the harbour on gunships and made the island their own. First came the Portuguese, rounding the Cape in their tall ships and happening on Zanzibar while searching for India. Then the Omani Arabs arrived, leaving their dry, barren homeland at the mouth of the Persian gulf and debunking to Zanzibar's greener and more welcoming shores, deploying thousands of slaves to build cool marble palaces and shady clove plantations. The last to arrive were the British, who reduced the Omani sultan to a puppet ruler - with the help of a naval bombardment or two - and set up a prim protectorate to go with their territories on the mainland.
But through three centuries of foreign domination, the Swahili inhabitants of Zanzibar had their own ruler, called the Mwinyi Mkuu, or Great Lord. The kings and queens who held this title enjoyed an uneasy truce with the invaders, being allowed to keep their status as spiritual leaders of the Zanzibari people provided they did not interfere in government. Although the Mwinyi Mkuu were nominally Islamic rulers, most of their power and status derived from their ability to control shetani and foresee the future. Hidden inside their stately palace at Dunga, in the interior, were said to be a set of magic drums that beat of their own accord whenever Zanzibar was in peril. The line of the Mwinyi Mkuu died out late in the nineteenth century, but the ruins of the palace still stand, innocuous enough in the daytime among tall, whispering plane trees, but said to be haunted at night by a host of fearful shetani.
As Hisdori finishes his story, the light goes out as if on cue, plunging us into pitch darkness. Electricity is rationed here, and the power is turned off every other night from 8 until 10. We find a stub of candle, and in its guttering light the whites of Hisdori's eyes glow dramatically as he regales me with tales of shetani he has known or heard of.
He begins with the best-known of them all - Popo Mbawa. Popo Mbawa, in fact, was more than just a run-of-the-mill shetani. He was a phenomenon. For a short time, back in 1995, American psychologists came to visit the island in order to write papers on the mass hysteria that gripped Zanzibar's population in the wake of Popo Mbawa's coming. Popo Mbawa began on the island of Pemba, where he terrorised the local population to such an extent that they called upon their fiercest sorcerers to drive him across the sea to Zanzibar. There his reign of terror continued - visiting people in their rooms at night, the foul-smelling demon paralysed them and then violated men and women alike.
People took to the rooftops and village squares, following a formless rumour that said safety could only be had by those who slept outside, in a group. But tales of the demon's progress around the island spread and spread, until the government was forced to take to the airwaves and plead for calm. 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 Mbawa retreated. He is widely expected to return, however, and when local people talk of him, it is with a nervous laugh.
Popo Mbawa was the daddy of them all, but 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 human beings, but it's a risky business. Dori has a friend called Sudi, whose father, a prominent businessman with a fleet of dala-dala taxis and a shopping centre on Creek Road, keeps a whole room of shetani in his house to promote material success and make mischief on his adversaries. A goat, a chicken or a cow must be sacrificed regularly and its blood sprinkled in the four corners of the room, or the shetani will take a terrible substitute - every year, it will demand one of its master's male offspring.