In the Western canon, Africa often gets treated as a quasi-supernatural arcadia, both seductive and unknowable a metaphorical and geographical Rorschach test that can be shaped like a gun or a skull or whatever else you'd like to see. Luckily, Theroux expeditionist, travel writer, and prolific novelist is too smart to over-romanticize the continent like that, even if the protagonist in his fantastic new book is not. Ellis Hock has spent most of his six decades on earth reminiscing about his years in the Peace Corps, where he once hewed out a life in a remote Malawian village. (Theroux's own youth included a similar adventure, and he's written several other books set in the landlocked republic.)
In his mind's eye, the place remains a ramshackle utopia where he could make a difference building schools and, quite literally, paving roads with his good intentions. So when his wife divorces him, he shuts down the men's clothing store he's operating in small-town Massachusetts and takes the opportunity to return to the land he recalls so rosily. Of course, reality quickly cracks her whip, and Theroux methodically dashes his character's expectations. ''The source of Hock's contentment, years ago,'' he writes, ''had been his trust'' in the innocence of the Malawian villagers. As Hock tries to determine if that innocence has been lost or whether he had just invented it in the intervening years, he gets caught up in a world that is not his own, and probably never was. Meanwhile, the villagers' opportunism born out of years of seeing well-meaning foreigners swoop into their country promising change, only to swoop back out soon after becomes less than friendly.
More in the tradition of The Heart of the Matter than Heart of Darkness, The Lower River is also largely a character study, and Theroux never lets Hock drift into a caricature of the self-aggrandizing white interloper. Hock grasps how vulnerable he is in this place, which makes the novel's darker turns that much more disturbing. He knows he is ensorcelled by exoticism, but he can't help himself. And, as things go from bad to worse and the pages start to turn faster, neither can we. A