Published between 1995 and 2000, the novels
Chaga (US title
Evolution's Shore) and
Kirinya, with the novella
Tendeléo's Story, form the 'Chaga Saga'--perhaps the most important and certainly the most compelling and moral redaction of the alien invasion story in recent decades.
The journalistic tag 'Chaga Saga', playing on Aga Saga, resonates with the female protagonists of each novel, but McDonald's purposes were far darker than domestic romance allows. An outer frame of the action involves the very real mystery of the dark side of Iapetus, but the principal story begins with extensive alien landings around the equator...meteoric biological packages that slam down and spill out an unstoppable wave of transformation. Animals are not directly harmed, but habitat is remorselessly consumed, and the major axis of
Chaga concerns the alien advance on Nairobi from an impact-site on Mount Kilimanjaro. The protagonist is Ulster journalist Gaby McAslin, whose outsider's eye both caresses African landscape and sees very clearly what the 'UN quarantine zone' is doing to Kenya and Kenyans. Gaby's story, with that of her daughter, continues in
Kirinya to a hugely satisfying space-operatic but also visionary and satirical climax.
Tendeléo's Story is an oblique coda, seen through the eyes of a young Kenyan girl who escapes to the UK only to be deported back to Kenya as an unwanted alien potentially contaminated by an even less wanted and much more alien alien.
The moral force of McDonald's plot derives from his use of the invading alien as an immensely powerful but also very slippery metaphor:
The image of the unstoppable wave of transformation was nicked from [1982 Star Trek movie] The Wrath of Khan: it's the Genesis device, slowed down, and once I had that, it became a rich source of metaphors: for colonialism, new technology, globalisation, change, death. If the Chaga is colonialism, it's a unique kind that allows the people of the poor South to use and transform it to meet their needs and empower themselves: it's a symbiosis.
The economic and moral issues are focused and driven home through the determination of the UN and the global pharmacological industry to conceal the fact that exposure to the alien Chaga cures AIDS, and the knife is turned by a fictional but verisimilar virology. In McDonald's 2008 (imagined in 1994-5) there are four strains of HIV: HIV4 is a death sentence for everyone, until the Chaga arrives, but HIV1-3 are death sentences only for the poor...showing very clearly McDonald's understanding (unusual in the mid-1990s) that AIDS was no longer a 'killer' in itself, but had become for the 'First-World' wealthy a manageable condition. McDonald's plotting is also, in
Chaga, deeply engaged with Conrad's
Heart of Darkness, and just as in Conrad the real horror is not only in the Congolese interior, but also in the looming bulk of late Victorian London, so McDonald's 'heart of darkness' is not the invading alien but the responses to it of the UN and of developed nations.