António Lobo Antunes's 1979 novel Os Cus de Judas was not the first colonial war novel to appear after Portugal's 1974 democratic revolution abolished censorship, allowing for the publication of such narratives. But its striking literary quality drew attention to those war novels as a recognisable sub-genre within contemporary Portuguese fiction, which the appearance of later works has consolidated.

Os Cus de Judas is set in 1979, but extensive flashbacks return us to the war in eastern and northern Angola in 1971–72. The narrator, a conscripted surgeon attending to young soldiers, observes the suffering and the havoc war has inflicted on African society. For him, the war proves a definitive event, for on his return to Lisbon all his old perceptions of and beliefs in his society have been utterly subverted. Although he has returned physically unharmed (a fortune not shared by many of the soldiers initially in his medical care), his new understanding of politics and life has completely destroyed his capacity for social reintegration. After twenty-seven months on the war front, he now leads an alcoholic, maladjusted, isolated life, having divorced soon after his return from Angola and lost old friends, who now find him too morose for company. The whole novel is a monologue delivered first in a bar, then at the narrator's flat, addressed to a silent woman who first shares drinks with him and then his bed.

The main reason for the narrator's failure to readjust to social and family life is the brutal and absurd experience of war. For the military surgeon serving not only his battalion but also other units dispersed in a vast circumference of enemy territory, the experience of death and mutilation becomes endlessly multiplied; and his professional eye recognises the signs of deep disturbances even in the lucky survivors of the surrounding carnage.

Set in Lisbon, the narrator's residence before and after his war service, the novel constantly contrasts different moments in his memory: his childhood and youth in the old, familiar milieu of the Lisbon of the 1950s and ‘60s; the shock of his immediately abhorrent encounter with the city of Luanda; and the trauma of his later posts in the war-torn Angolan interior.