At home in San Francisco, between research trips to Africa, renowned primatologist Suzanne Albrecht finds herself suffering from an unexplained fever. Dr. Tony Miller, one of the sharpest diagnosticians in San Francisco, is determined to uncover the cause.
But Suzanne doesn't have time for hospitals and multitudes of tests; she's scheduled to return to Africa to continue her research on the bonobos, a species of pygmy chimpanzees. Still concerned about her medical condition, she persuades the single handsome doctor to accompany her on her trip abroad.
Tony accepts the invitation, but once in Africa, he soon finds himself facing perils he hadn't imagined. Not only do Tony and Suzanne become embroiled in a tense political situation that almost costs them their lives, but Suzanne's condition continues to worsen. Tony must solve the riddle of Suzanne's mysterious illness while confronting his true feelings about Suzanne, who is an enigma herself.