Sam and Florence Baker appear briefly but memorably in accounts of the mid-Victorian fever to discover the Sources of the Nile. He is seen as a burly big-game hunter and something of a spellbinder; she is his petite, self-possessed young Hungarian wife; and together (the story goes) they endured unspeakable hardship and danger to reach the mysterious inland sea--then conceived as a tributary of the Nile--which they neatly named Lake Albert. All true enough, except that not only was Florence not then Sam's wife--as a few knew and others, including Queen Victoria, suspected--she had been plucked by him from a Turkish slave market. Hall learned the shameful, enticing truth from family papers; and one can only marvel the more at Florence's adapting with equal sang-froid to life as Lady Baker--gentleman-explorer Sam was quickly knighted--and to life in deepest Central Africa. The public, or social, side of this unconventional liaison is more effectively rendered here, in fact, than the private side. Hall dithers about expressing the apparent passion the two had for one another, and takes refuge in wondering why devoted Sam ran the risk of Florence's becoming pregnant Away from Everything (trust in the new condoms? in her two-years' barrenness?). But that research-rootedness pays off when Hall traces, in journal entries, Sam's shift from indecisiveness about the unidentified ""F""--now that he's returning to England, shall he part from her or keep her?--to firm resolve, in the form of the first, moving (if premature) reference to ""my wife."" British journalist Hall is best known here, however, as the last, most searching biographer of Stanley (1975), and this is at least equally the story of the Bakers' sore-beset travels and the rivalries among Africanists. We see Florence coolly intervening to rescue impetuous Sam, and Sam imaginatively hoisting a Highland plaid sail on Lake Albert. We see the brilliant Richard Burton about to debate his slow-witted critic Speke--and the latter killing himself in despair. And we also see, as Sam returns to Central Africa in the employ of the Egyptian khedive, how European penetration backfired: the very Africans he had counted on to help him stamp out the slave trade were so implicated, now, that they were ready to butcher him. If Hall does not succeed in making a rousing narrative of these marvelous materials, he does recognize their individual worth; and readers of various bents will be in his debt.