After fighting the communists in Finland, Max Manus returns to Norway, currently occupied by the Nazis. He joins with the Norwegian resistance movement in their fight against the Germans but is arrested. He manages to escape to Scotland where he receives training before being sent back to Norway to carry out sabotage missions against the occupying forces.

Returning to Norway with his friend Gregers Gram, his first mission is an attack on German supply ships. He is spectacularly successful, and soon he becomes a special target for the Gestapo commander Siegfried Wolfgang Fehmer. Manus, however, avoids capture, and with Gram and Gunnar Sønsteby he forms the so-called “Oslo Group”.

Stockholm becomes a meeting point for Norwegians in allied military service. Here Gram introduces Manus to Tikken, who works as a Norwegian contact for the British consulate and the two soon develop a special relationship.