Jean Piaget, the Swiss educator and theorist with whose thought Susan and Nathan Isaacs were closely involved, paid a visit to the Malting House School in 1927. The personal arrangements at the school lasted until that the end of that year. They were undermined by two love triangles. Susan had an affair with Pyke: it was a short fling, around the end of 1925, about which Pyke's wife Margaret knew at the time, but Nathan did not. It was followed by unreasonable behaviour on Pyke's part. Nathan, subsequently, had an affair with Evelyn Lawrence, who joined the staff as psychologist in 1926. Nathan became her lover in August 1927, as Susan knew at the time. The Isaacs' left the school soon after. By that period, Pyke was running out of money and sold his interest in the school to Edgar Obermer (1895–1958), one of the parents; with further funding Pyke kept the school going to 1929, when he had a serious breakdown and it closed. Nathan Isaacs continued to work as a metals merchant, and during World War II was a civil servant in the Ministry of Supply. Evelyn Lawrence left Malting House School in 1928. After some time outside London, she started to share a London flat in Primrose Hill with her sister Hilda, close to where Susan and Nathan Isaacs were living: her affair with Nathan was ongoing. In 1943 she became director of the National Froebel Foundation. Susan knew of this relationship, and continued to relate well to Nathan intellectually: she concentrated on writing her book based on observations at Malting House. After the outbreak of World War II, Isaacs initially continued to work in London; while Susan was based in Cambridge. During The Blitz the Ministry of Supply was moved out of London, and Isaacs was posted to Ashow in the Midlands for most of the rest of the war. Susan travelled there at weekends. Nathan saw little of Evelyn during this time: she had been evacuated at Torquay. In 1945 Isaacs returned to London, with a job at Derby & Co. He was awarded the OBE for his war work, in 1948. In 1946 Susan began to succumb to recurrent breast cancer, and she died in October 1948. She made clear her wish that Nathan, her carer, and Evelyn should support each other. They were married in April 1950. While Piaget's early books met with criticisms formulated by Susan and Nathan Isaac, his later methodology was somewhat different.