Christian Barnard from Capetown didn't write the great success-story of the first heart transplantation in 1967 alone. Hamilton Naki, a black man, was equally part of the sensational operation. «Hidden Heart» tells the story of two men, glamour, injustice and uprising. The documentary combines Barnard's and Naki's career paths in the respective political context and works out undeniable parallels in the character of the two men, showing the possibilities for professional development within the political system and the way they each dealt with it and what they made of it. And finally, the film will shows how history can be rewritten when a system seemingly cemented in place for eternity, falls apart. The story of the two men not only recounts the heart transplant in a new light but also shows how determination and discipline - characteristics possessed by both men - can move mountains. The mountain moved by Barnard went down in the history books but this does not make Naki's achievements any less - when recounted in the political context of the time. «Hidden Heart» knows no taboos, neither in its treatment of Naki nor of Barnard. The two are to be examined critically yet fairly through a multifaceted kaleidoscope of testimonials from carefully chosen witnesses from the period.