The Brothers M are Bob McNair, a Canadian, and Daudi Mukasa, a Uganda Negro, who meet at Oxford. Their friendship, a ""fateful growth"" continues when McNair joins Mukasa in Africa, on his search for his mother's people- and her twin sister- a remote and ragged tribe high in the Ruwenzari mountains. This, however, is only the superficial scaffolding of a narrative which is primarily a very subjective inquiry into the divergence between black and white, not along national or political lines, but social and racial and psychological. Mukasa, a haunted man, is lost between two worlds- of the civilized European and the primitive African, and while David is insistently defending the individuality of modern man, Mukasa's return to the tribe is in the hopes of establishing the superiority of his ancestral, collective environment, the contentment of an ordained and therefore ordered life on which the new and false gods (freedom, truth, progress, etc.) do not intrude. As the two make their safari up into the mountains (and there is a staggering amount of information on the indigenous, tribal ways as well as the natural menace of the jungle) they face further, unexpected irreconcilables; violence flares; Mukasa -- his mind darkened by regressive, superstitious pressures- is vulnerable to suspicion and betrayal; and the journey ends in disaster establishing the hopeless chasm between the white man and the black, ""two incompatibles... two harsh constituents"".... Whatever reservations one may have about the book as a novel (its ambitiousness; the overseriousness of the brothers M as they pursue and prod cosmic truths), there is no question of the sincerity of its intent and the genuineness of much of this African experience. While it may well daunt the general reader, it should provoke thoughtful comment.