Late in 1961, this author withdrew, under pressure, from U.N. service and resigned from the Irish Foreign Service ""in order to recover my freedom of speech and action"". His first act on regaining that freedom, and in direct contradiction to the U.N. regulations, was to write an account of his six months in Katanga, as Dag Hammerskjold's representative. His task had been the implementation of a Security Council resolution calling for the immediate withdrawal of all foreign officers and mercenaries from Katanga. By his use of U.N. troops he drew down the wrath of countries interested in maintaining the status quo -- Belgium, France and Britain. His naive expose of their intrigues led, he believes, probably rightly, to a display of power politics in the world's forum and eventually to his withdrawal from the U.N. Mr. O'Brien's apologia is not entirely convincing but it contains some fascinating glimpses behind the scenes at the U.N. and reveals African personalities uninhibited and with plenty of inflammatory material. In this country it is unlikely that the book will arouse the furor it did in England. The text is dry and liberally interspersed with literary references. As an inside account of U.N. intervention in the Congo, the book in welcome for the partial light it sheds on a much publicized country and a period shrouded in misconception and lack of understanding.