None of the tourists aboard the St. Buryan had known of the quarantine before leaving New York. Now they realize that once they go ashore at St. Hubert, they will be prisoners there for the duration of the epidemic.
Martin begins to wish that he had forcibly left Leora behind and tries to convince her that she should stay on the ship, but to no avail. Upon landing, the travelers are met by Dr. Stokes, the port doctor having died a few days before. Many of the servants are also dead, and hotel living is by no means comfortable. Martin hopes that Leora does not see a wagon piled with a dozen dead bodies which they encounter on the street. The spirits of Sondelius, however, are still high, and he dons a dressing gown of surah silk last worn on the East Coast of Africa. Inchcape Jones has scarcely finished his call on the newcomers when the new arrivals have another caller, the Rev. Ira Hinkley, now at work saving souls and incidentally bodies in the plague-stricken area.
In the afternoon, Inchcape Jones takes the Commission to his home, Penrith Lodge, in the hills behind Blackwater. On the way, they pass a schoolhouse turned into a pest house, with a hundred cases of plague within. Martin establishes a small laboratory with the equipment he has brought. His first caller is a black doctor, Oliver Marchand, M.D., who is familiar with Martin's experiments and is doing all he can to fight the plague.
While Martin is establishing his laboratory, Sondelius launches his anti-rat campaign, terrifying the Board of Health and dragging people of all occupations from their work to follow out his instructions.
Again Lewis unifies the novel by bringing in still another member of Digamma Pi after years of absence from the story — Ira Hinkley. Ebullient and obnoxious as ever, Hinkley is still detested by Martin Arrowsmith.
All the sordid happenings of the chapter are set against a background of natural beauty of the tropical West Indies. Only one new character is introduced, the black doctor, Oliver Marchand, progressive, well-read, efficient, and dedicated to his profession.