Martin becomes a volunteer assistant to the Superintendent of Health, Dr. Woestijne. He denounces accumulation of dirt and trash in yards and streets and criticizes the school board for lack of building ventilation and instruction in tooth brushing. He traces the origin of the typhoid epidemic to a seamstress, who is a carrier, and launches a campaign for smallpox vaccination. When all but the first case turn out to be chicken pox, Martin is the butt of ridicule and feels that he is "licked." He and Leora decide to move on to a larger place.
Through the influence of Sondelius and upon the recommendation of Dr. Silva and Professor Gottlieb, Martin obtains an assistantship in Nautilus, Iowa, not far from Zenith, under Dr. Almus Pickerbaugh, Director of Public Health. His salary is to be twenty-five hundred dollars a year. He will be epidemiologist, bacteriologist, manager of clerks and nurses, and inspector of sanitation. He and Leora board the train after apologetic and regretful farewells by such neighbors as Pete Yesta, Dr. Hesselink, and Henry Novak.
The Wheatsylvania episode is now finished, and Martin and Leora move out of North Dakota to Iowa and a different life. The fact that Martin's tormentors regret his going is proof that they appreciate him more than he thinks. A new phase of the story, the Nautilus one, is about to begin.