Pink dolphins--and yes, in the Amazon River the flamingo-colored mammals do exist--are believed by Brazilians and Peruvians to take human form, impregnate women, lure lovers to an underwater paradise, and in various ways drive those who encounter them mad. They seem to have worked their magic on science writer Sy Montgomery, who journeys through rain forests and sunken cities in a mad-dash pursuit of the enigmatic creatures. Despite encounters with piranha-filled waters, toxic ants, and large rats--not to mention boat failures, foreign language problems, and alternate blasts of sun and rain--the persistent Montgomery pushes happily on, offering a lyrical account as intoxicating as the subject itself. She eventually makes contact, swimming with them, even holding one in her arms, but that may be the least relevant aspect of the entire book. Montgomery turns nature into a bewildering drug, opening doors into cultural and biological worlds invisible to most, but which teem with as much unseen life as a drop of river water held under a microscope. --Melissa Rossi