In this interview excerpt, Sir Brian Unwin, a diplomat in the British Foreign and Commonwealth Office from 1960 to 1968, describes the suspicious circumstances surrounding the death of Dag Hammarskjöld, United Nations Secretary General from 1953 to 1961, during the night of 17 to 18 September 1961. Dag Hammarskjöld was flying into Ndola, in Southern Rhodesia, to meet Moise Tshombe, Prime Minister of the independent Province of Katanga, which was in conflict with the United Nations. Sir Brian also mentions the subsequent enquiry into Hammarskjöld’s death.