Krug, the protagonist, begins the novel looking out the window at the sky, at its reflection in puddles, and at the trees lining the street. He muses on their changing colors and resemblance to other scenes he has known. Soon, it is revealed that he is in a hospital. A nurse who comes in recommends that he stay there overnight because there is fighting going on the city, and if he leaves at night, he is in danger of getting hit. Krug says that he has a pass, and the fighting is not of his concern.

“I am not interested in politics,” he said. “And I have only the river to cross.”

As Krug leaves, he begins to cry and continues to cry as he walks along the street toward the bridge by which he will cross the river. His description of the street furthers the associations of color, light, reflection, and mood that Vladimir Nabokov had introduced in the opening passage about the sky and the puddles. This concern with color and reflection continues throughout the novel.

On other nights it [the bridge] used to be a line of lights, lit with a metrical incandescence with every foot rescanned and prolonged by reflections in the black snaky water. This night there was only a diffused glow where a Neptune of granite loomed upon his square rock which rock continued as a parapet which parapet was lost in the mist.

Later, at home, Krug receives a phone call from the university asking him to come and help them out with an unspecified matter. They send a car for him, and, arriving at the office, he finds the other professors already assembled, waiting for the event to begin. Gradually, it is revealed that they are all preparing to sign a petition to the head of state, “the Ruler,” an old schoolmate of Krug’s, and want him to take the signed document to him. Krug not only objects but also insists that his sole relationship with the Ruler—whom he calls the Toad—had been to beat him when they fought every day and to sit on his face. Therefore, he is obviously not the right person to deliver any missive.

Reading the manifesto, Krug pulls out his pen and, when the others think he is going to sign it, instead inserts a single comma.

“Sign it,” said the President in a funny automatic voice.

“Legal documents excepted,” answered Krug, “and not all of them at that, I never have signed, nor ever shall sign, anything not written by myself.”

It turns out that this “manifesto” is the faculty’s agreement to add to the curriculum political teachings that support the Ruler’s policies, which Krug refuses to endorse. As the novel progresses, the relationship between him and the Ruler, whose name is Paduk, is further detailed. Finally, after some of the colleagues are arrested, Krug is taken to see Paduk, who tries to convince him to support his regime.

Paduk explained . . . that Krug was to be nominated college president in place of Azureus. His salary would be three times that of his predecessor . . . . Moreover, he would be provided with a motor car, a bicycle, and a phonograph. At the public opening of the University he would kindly deliver a speech. His works would be republished in new editions, revised in the light of political events. There might be bonuses, sabbatical years, . . . lots of things.

Krug’s refusal to give the speech leads to his ultimate undoing, as he and his son are arrested. After his son is killed, that proves too much for Krug to bear, and he loses his mind.