Coup de grace is set in an unnamed Baltic State, in 1919 After the Russian Revolution, the defeated Germans sent volunteer troops to join the Expeditionary Forces fighting the revolutionaries At that time, many German nationals lived in Baltic countries, where German Communists fought alongside local, nationalist Reds.

The film relates the story of two friends, both young German officers, who return to their home town to fight the revolutionaries Sophie (Margarethe von Trotta), the sister of one of the officers, falls in love with her brother's friend, but is continually rebuffed by the latter Her political sympathies are ambivalent despite her love for the Prussian officer, she remains friendly with several German officers in the revolutionary camp When she realises that the officer she loves has had an affair with her brother, she throws in her lot with the revolutionaries.

Shortly before the German retreat, leaving the country to its fate, she is captured, and now she is to face the last confrontation with the man who meant everything to her.

Schlöndorff describes the film's interest: ‘It is the story of a man fascinated by a woman, or rather, fascinated by the love she offers him. It depends on the individual spectator whether he is more interested in the kind of love offered to this man or in the man himself. The interesting thing is that the story starts in 1919. The more the story unfolds, the more we can rediscover ourselves in it and recognise the traits of Prussian tradition and German history anchored in all of us.'