As I write this, in Lawrence, Kansas, news updates on Barack Obama, the Democratic Senator from Illinois, dominate the airwaves. Senator Obama is currently visiting Kenya, the East African country from where his father famously hails. Stupendous crowds are, according to reports, defying insuperable odds to catch a glimpse of the dashing Senator and his wife, Michelle. Momentarily at least, Kenyans have cause to smile – and hope. Should Obama deliver on his potential and attain senior office it would certainly be something for Africa to celebrate. But when, at the end of this brief 'homecoming', Obama and his scrum of reporters and photographers depart for the United States, life in Kenya will assuredly return to normal – to the same postcolonial mess in which hope is inevitable yet unaffordable, reality takes on the aspect of fantasy, and, as Ngugi wa Thiong'o describes in his powerful new novel, "power daemons" sit on the throne for so long that "they begin to forget when they actually got there."

In his acknowledgments at the end of this sprawling book, Ngugi provides a clue to the actual models for the chain of events set out in Wizard of the Crow. He thanks several compatriots who took part in the struggle for the release of political prisoners in Kenya between 1982 and 1987, and fought against iron-fisted dictatorships in other locations: the Philippines under Ferdinand Marcos, Chile under Pinochet, and South Africa under the apartheid regime. Although life in Ngugi's ironically named 'Free Republic of Aburiria' is a barely disguised extract from the pages of postcolonial Kenya's sullen history, the Republic of Aburiria is, more precisely, a composite of lives as familiarly (and tragically) lived in most parts of Africa and the Third World.

There is hardly a writer better placed to tell this story than Ngugi, alumnus of the notorious Kamiti Maximum Security Prison in Kenya, and witness to postcolonial violence at its most savage (most recently in the form of sexual assault on his wife Njeeri, an incident widely believed to have been orchestrated by his old foes within the Kenyan state). Ngugi's entire corpus, comprising fiction, plays and memoirs, has found its creative focus in the exposition of the constant existential flagellation that is life in Kenya, and the train of life in Aburiria is, not surprisingly, powered by the same steam of violence, corruption, fantasy and sorcery.

Reading the book, and submitting oneself quite easily to the implausible escapades of the cast of 'daemons' at it's centre – Markus Machokali, Aburiria's Minister of Foreign Affairs, John Kaniuru (Johnny the Nose), Silver Sikiokuu, the Minister of State, and Benjamin Mambo – there is a strong temptation to conclude that Ngugi himself has succumbed to the devious charms of the 'magic realist' approach most directly associated with Gabriel Garcia Marquez. Indeed, Wizard of the Crow teems with tall tales – of eyes becoming improbably big, ears impossibly wide, and noses unimaginably extended. Yet, the very process by which the seemingly improbable transmutes into the ordinary is, I think, the exact point Ngugi aims to drive home.

No shrewd observer of postcolonial Africa can fail to discern, whether in the unnamed Ruler, or in the Machokalis and Kaniurus and Mambos and Sikiokuus of Aburiria, or for that matter in those that resist them like Karimiri and Nyawira, uncanny echoes of concrete historical figures who have honoured and dishonoured, Africa's postcolonial history.

As a Nigerian, I find myself not only recalling the horrors of my fatherland's recent ordeal in the hands of nameless Rulers (military or uncivil), but also mentally re-enacting my experiences with its "crooked roads, robberies, runaway viruses of death, hospitals without medicine, rampant unemployment without relief, daily insecurity." When I think of how the most significant political figures in Aburiria are overcome by the mystical promise of surgical enhancement, I am reminded immediately of how their actual counterparts in contemporary Africa have made a lifestyle of cosmetic surgery, flying to various European capitals to have their bloated tummies tucked, while their pitiable subjects gorge themselves on, er, nothing. As we speak, politicians in Kenya (insert African country of your choice) explore new frontiers in graft, stashing looted public money in foreign headquarters of the Global Bank.

Most of those who lined the streets of Kibera, Kenya, to welcome Obama are poor, diseased and illiterate – just like the citizens of Aburiria. Ngugi has written a compelling, disturbing and urgent account of the African present.