 In 1961 he became a founding member of the Hoddesdon Society "set up to protect the town from tower blocks and excessive development that did not fit in with its historic architecture", remaining the Society's president for a number of years.In 1973, Tree's friend, director Nicolas Roeg, persuaded him to return to the screen in Roeg's horror film "Don't Look Now", playing the role of an ineffectual headmaster.The Tree family manor provided the exterior and interior for the opening sequences as did his lake, where the red anoraked girl drowns.