The novel is set in an imaginary country. The plot follows the life of Second Lieutenant Giovanni Drogo from the moment he becomes an officer and is assigned to his first posting at the Bastiani Fortress, far from the city. The Fortress, the last outpost on the northern border of the Kingdom, dominates the desolate plain called the “Desert of the Tartars”, once the scene of devastating raids by enemies. However, for countless years, no threat has appeared on that front; the Fortress, now devoid of its strategic importance, has remained only a building perched on a lonely mountain, whose existence many are unaware of.