This is my wonderful friend Peter Mitchell, in the garden of his house Glyn in Cornwall. In the other photo he is with his wife Helen, with whom Olivia had a close friendship. Peter was one of the most brilliant scientists of the 20th century. He won the Nobel Prize for Chemistry in 1978 for discovering vectorial metabolism. I wrote several articles about him in such publications as The Economist. Our nickname for Peter was ‘Beet’, which is what his grandchildren (who mispronounced ‘Pete’ as ‘Beet’) had called him, and he loved to be called that. Beet had such a wonderful sense of humour. He recommended me for a Guggenheim Fellowship, but they refused to give it to me, probably because I was too odd. Beet honoured me by calling me his ‘co-conspirator’. He also introduced us to the joys of Volnay, the smoothest of all the burgundies. Beet was one of the most remarkable men I ever knew: sensitive, intuitive, witty, brilliant, and fun. He was also so self-effacingly modest that he would have liked never to have been noticed by anyone, and to have been invisible. And now he is.