David Diop’s novel At Night All Blood Is Black is an exploration of human psyche during the Great War. The brutality and savagery of World War I is the primary theme of the novel. The violence and bloodshed in the war affect the mind-set and overall human psyche. Alfa Ndiaye is the protagonist of the novel. He narrates the present and past, and intermingles the brutality of war with inherent goodness in human relations. Human connections are always at the centre, whether the situation is favourable or unfavourable, good or bad, local or global, natural or man-made. The narratives focus on friendship between Alfa Ndiaye and his childhood friend, one who is referred to as his more-than-brother, Mademba Diop. The deaths of Mademba Diop, Jean-Baptiste and a young enemy soldier narrated in the novel present the cruelty and savagery of war. In flashback, the stories of the narrator’s father, Bassirou Coumba Ndiaye, his mother, Penndo Ba, his first love, Fary Thiam, and the simplicity, trust and innocence of the Fula shepherds reflect human connections at different levels. The simple practices of the narrator’s father, Bassirou Coumba Ndiaye and his arguments regarding cultivating food grains and vegetables instead of cash crops reflect social sustainability goals. The present research is an attempt to explore the brutality of war, human connection, and social sustainability as reflected in David Diop’s At Night All Blood Is Black.