Denmark 1851. Young brothers Laust and Peter grow up in poor but safe conditions on the local estate in south Funen. As their father returns with other soldiers, victorious from a three-year war with Prussia, Laust and Peter become enamoured with the new estate manager’s daughter, the beautiful and fearless Inge. Political forces consider incorporating Schleswig into the Danish kingdom, contrary to the signed peace treaty. Prime Minister Monrad is inspired to patriotic eloquence by a perfomance of Macbeth, with the enticing Mrs Heiberg acting as his muse as the ruthless and manipulative Lady Macbeth.
As Laust and Peter grow up, they are both in love with Inge, who loves them both in return. Peter dreams of seeing more of the world, his interest piqued by the arrival of a family of travellers on the estate. On the politcal stage, the driven and somewhat unbalanced Monrad succeeds in stirring up a national euphoria in Denmark, a belief that the province of Schleswig has been given to the Danes by God. The Baron, seized by this nationalistic zeal, persuades the brothers of their duty to join the army.
Monrad forces a new constitution through parliament that incorporates Schleswig into the Danish kingdom and, as expected, triggers a declaration of war from Prussia. Laust and Peter meet their young comrades-in-arms, as well as the experienced and mysterious Johan, and get a taste of how real the horrors of war can be. The brothers exchange letters with Inge, but Laust also sends her secret letters.
Peter and Laust reach Dannevirke where they are dismayed to find the historic defences almost useless, and are further disheartened to learn that their new captain is none other than Didrich. General De Meza decides, against the will of the powers-that-be in Copenhagen, to withdraw to Dybbol.
Following the shaming evacuation of Danevirke, the retreating Danish troops are harried by bloodthirsty Prussian hussars. Laust’s division is caught in a fierce snowstorm and he is ordered to retrieve an artillery piece from a frozen lake. Expelled by her family, Inge travels south towards Sonderborg to find Laust before their baby is born.
Arriving at Dybbol, Inge and Sofia try to find Laust and Peter, but a chance meeting with Didrich dashes their hopes. The Danish forces are bogged down in the town and when the Prussians start a bombardment the senior officers demand a retreat – only to be denied by Copenhagen. Claudia visits her mother and discovers a box filled with family secrets.
The Danish soldiers are totally outnumbered as the Prussian and Austrian forces prepare to bombard the defences at Dybbol. Johan has foreseen the terrors which are about to take place and tries to warn the complacent commanders. Peter learns of Inge’s pregnancy and is now determined to find Laust.
The shock of defeat is difficult for the politicians in Copenhagen to accept. Monrad accuses the king of treason for attempting to negotiate with the Prussians. Johan seeks out the families of the fallen and gives Inge’s mother Laust’s last letter. The news he has for the Baron is too hard to bear. Peter returns home a changed man.