Gunnar Sonsteby is the most highly decorated hero of the Norwegian resistance. Ironically, he almost went to work in Germany six months before the invasion of his country. He did not, and when the Germans came, he was around to say, ""So there I was in German occupied Oslo."" What he did there and then until the liberation defies the reader to keep his coolth, although Sonsteby apparently always managed to maintain his. Starting out as the clandestine paper boy for a clandestine newspaper, he eventually became the sabotage leader of the Central Committee of the Home Forces, the chief of operations in the Norwegian Resistance Movement and head of the Oslo Gang. His exploits included blowing up the Labor Offices capturing a load of ration cards, heavy water sabotages demolishing the Korsvall garage with its 24 Messerschmidt fighters and 150 airplane motors,- the Kongsberg arms factory and securing the Nazi archives. After the liberation he became chief of Crown Prince Olaf's bodyguard and brought Quisling to his trial. As prosaic an accounting as the material is dramatic; but Mr. Sonsteby's quick-witted competence and courage are constantly in evidence.