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 meet their new Captain - a familiar face from the estate back home - but not exactly a happy reunion. Laust and Inge continue their secret letter writing but an incorrectly delivered letter causes serious consequences for the relationship between the otherwise inseparable brothers. Dannevirke turns out not to be nearly as impregnable as people have been boasting, and General De Meza decides, against the will of the powers that be in Copenhagen, to withdraw from Dannevirke to Dybbøl.

Following the evacuation of Dannevirke, the Austrian Hussars are ordered to hunt down the Danish troops. This leads to a fatal encounter when they catch up with Peter's division. Laust's division is caught in a fierce snowstorm and an accident nearly causes the death of Laust. Laden with guilt and in a feverish haze, he wishes to admit everything in order to save his relationship with Peter. Expelled by her family, Inge travels with the gypsies towards Sønderborg in order to find Laust.

Inge and Sofia reach the front where they come face to face with the harsh realities of war. An encounter with Didrich leaves Inge without any hope of ever seeing Laust or Peter again so she volunteers as a nurse at the camp hospital. Laust is ill and needs his brother but Peter is a changed man - wounded by the horrors of war and Laust's betrayal. In Copenhagen the reality of the situation is beginning to sink in but despite the bombardment of Sønderborg, the government maintains that Dybbøl must be held at all cost.

Intoxicated and obsessed with the thought of hurting Peter and Laust, Didrich reveals to Peter that Laust and Inge harbor a secret. Peter decides to find Laust to make peace with him. A warning of the terrors that lie ahead shakes Johan to the core and he tries desperately to prevent the events that follow. Despite huge numbers of casualties, Copenhagen still maintains that the Danish army must persevere.