On 9th April 1940 when the Germans invaded Norway, many of the officers who were at the spearhead, were men who as teenagers in the First World War, were evacuated from Vienna to escape the Italian bombing, to stay with kindly and hospitable Norwegian families. They were especially chosen because they possessed an unusual intimate knowledge of the Norwegian people, their country and their language, It was Winston Churchill who gave them their contemptuous name "Vengeful Cuckoos" returning to foul the very nests that had once given them loving sanctuary.This is the story of one of them, Kapitan zur See Otto Wilhelm Schmidt, 38, a German naval officer, in command of "Essen" a destroyer converted as a mine layer, ordered to return to Hæranger, a small fishing town on the edge of a fjord in Southern Norway, ordered to act as civil administrator until such times as the occupation is complete when specially trained personnel will take over. Wilhelm believes the occupation of Norway is to protect the people from the aggressive British plans to invade Norway and is determined the occupation of Hæranger will be as peaceful as possible. This does not meet with the approval of Oberleutnant Fritz Goetz, his second in command, who is arrogant, overbearing and secretly a member of the Abwehr, the German military intelligence. Wilhelm despises Goetz and the Nazi party that has produced him and others like him.Formally presenting himself to the Mayor of Hæranger, is shocked when he discovers the man with the gold chain of office is John Hermansen, the head of the family who kindly took him in as an evacuee, and his daughter Kristin with whom he had a youthful romance, now a poised and beautiful women, acting as Deputy mayor as her mother has sadly passed away. Nils overhears Wilhelm announce the adult population are to be conscripted into forced labour. He goes to meet Olav his father who is returning from a business trip to Oslo and persuades him not to come home, but go to Lågholm high up on the mountain ridge, backed by huge mountains on one side, and protected by dense forest on the other three, the perfect hideaway. Ragnhild, a beautiful girl in her early twenties who was assaulted by Goetz by deliberately frisking her in a very intimate manner, decides to fight her own war against the invaders by alluring the sailors with the promise of sex and then killing them with a stiletto she keeps hidden in the top of her stockings. Svein Lauritsen, principal of Hæranger's further education college refuses to obey the directive to introduce Nazi ideology into the college curriculum and is arrested and sent on a harrowing train journey, along with other teachers who have also refused, packed together in cattle trucks to Grini concentration camp.Many wanting to seek revenge on the German occupation, slowly make their way to Lågholm to join Olav and Nils. Soon they have enough men to form a resistance group and begin to attack German supplies. Nils is caught spying and is sentenced to be publicly executed in the town square. Suddenly torn between his duty to the Reich and his desire not to deal too harshly with the people as disobedience and the resistance grows, Wilhelm finds himself under pressure from the Gestapo and is forced to adopt stronger and more oppressive measures. In the midst of the turmoil, Kristin reveals to Wilhelm the secret she has kept from him for years that Nils is actually his son. The revelation propels him into a decision to save Nils from execution he is forced to compromise himself and seek the help of the resistance.An elaborate, but risky plan is put into place by the resistance and as a consequence Wilhelm finds himself overwhelmed by the developing situation that reaches a dramatic and explosive climax.
