In 1970, Nicholas Garrigan graduates from medical school at the University of Edinburgh. With dull prospects at home, he decides to seek adventure abroad by working at a Ugandan missionary clinic run by Dr. David Merrit and his wife, Sarah. Garrigan becomes attracted to Sarah, who enjoys the attention but refuses to engage in an extramarital affair.
Meanwhile, General Idi Amin overthrows incumbent president Milton Obote in a coup d'état. Sarah has seen past corruptions and warns it will repeat itself, but Garrigan sincerely believes Amin will help the country.