James Barber FRS, was a leading investigator in the field of photosynthesis for over 40 years. This volume summarizes his contributions, ending with his most important work on how plants make oxygen, a molecule that is essential to our life on our planet. His contributions over the years took a zigzag course dependent on many factors which university based scientists have to deal with including maintaining continuity of effort. Each step in the journey is moulded by the knowledge current at time, slowly progressing to his final goal, obtaining the high resolution of structure of the oxygen evolving enzyme and thus providing a blue-print to construct a technology to produce renewable carbon free energy for the future survival of organised human society on our planet. A selection of his papers are used to provide the stepping stones for his journey which stretch over almost 50 years. It is a story of what seemed impossible becoming possible and an inspiration to young scientists just starting their careers.