Iris MacFarlane was the wife of a tea plantation manager in Assam in the 1950s. Green Gold begins with her account of life in Assam during this period, observations of the living and working conditions of workers on the tea estate, and the challenges to her attempts to improve them. The main book by her son, Alan, traces the history of tea, its links with the British Empire and its impact on those that grow, trade in, profit from and drink it. He quotes extensively from historical documents including first hand accounts from tea pioneers as far back as 1866.