In which Martin Arrowsmith, an eager medical student, observes the precise and impersonal laboratory work of Professor Max Gottlieb as he inoculates guinea pigs with anthrax, imparting lessons on scientific technique and the gravity of experimentation. Amidst this atmosphere of careful study and somber reflection, Martin experiences a growing fascination with the craft of bacteriology, culminating in a quiet camaraderie and midnight conversation that reveal the older man’s tempered idealism and struggles.