Blücher is a film about Colonel Birger Eriksen's role during the most dramatic hours in Norwegian history. It's a suspenseful drama about the biggest decision in the colonel's career. The decision had consequences for the course of history, as events unfolded on the night of April 9, 1940, when the aging 64-year-old colonel commanded Oscarsborg Fortress, a critical passage that all ships approaching Oslo had to pass.