If that were all to the story, then it would not have had the success it did. However, there is a lot more. Lieutenant Drogo is assigned to the remote Fort Bastiano, on the outposts of the Empire. What the Empire is, is never made clear by Buzzati. Presumably it is the Austro-Hungarian Empire, though the geography does not always fit. Specifically, where the fort is located is very ambiguous. Apart from the fact that it is on the boundary of the Empire, all we know is that it is next to the Desert of the Tartars (or the Tartar Steppe, as the English translation has it). It seems to be near (the unspecified) city Drogo is from but yet he and others have difficulty in finding it and get lost. As to its neighbours, it is next to the state in the North but this state is never named and the Tartars may be separate from them. The Tartars may be the Tatars or they may not. In short, it is something of a mystery, a phantom.
Drogo does manage to get to Fort Bastiano, where he finds a strange collection of men. They want to get away and yet they don't. One officer, for example, has been there eighteen years and claims to have seen the mysterious Tartars from a distance. He is awaiting their return so that he can attain glory in battle (there are no other wars going on). Though this officer eventually becomes commander of the fort, his opportunity never comes. Not much happens at the fort and Drogo is soon seeking a way out though, somehow, it doesn't quite work out. A mysterious white horse appears - riderless. It may or may not be a Tartar horse. When one of the soldiers goes out to get it - without authorisation and entering foreign territory, he is shot on his return. In fact, given that there is little else, military discipline can become an obsession with some of the officers. Further glimpses of the Tartars take place. Or do they? There is always some doubt as to whether they are really there or whether it is just a trick of the light. At one time they are apparently surveying the frontier, though the officers are already for a war, which never comes.
With a lesser author, this could be very boring but Buzzati handles it so well. His use of time and the passage of time, which seems relative rather then absolute, is excellent. How much time has passed? We never seem to know, suddenly jumping forward years in a short space of time. In particular, when he is away from the fort, time takes on a different dimension as everyone else goes about their normal business while he is seemingly in a different time zone. He gets promoted, reaching captain but, at the same time, gets ill. It is, of course, at that point that the Tartars really do attack. However, by the time that they are actually mounting the attack, he is ordered to return to the city for his health and he leaves as they attack. Buzzati has left us with a very fine novel about time, particularly relative time, about waiting and expectation, about how we face (and don't face) reality.