A medical researcher is sent to a plague outbreak, where he has to decide priorities for the use of a vaccine.

Ronald Colmanas Dr. Martin Arrowsmith
Helen Hayesas Leora Tozer Arrowsmith
Richard Bennettas Gustav Sondelius
A.E. Ansonas Professor Max Gottlieb
Clarence Brooksas Dr. Oliver Marchand
Alec B. Francisas Twyford
Claude Kingas Dr. Tubbs
Bert Roachas Bert Tozer
Myrna Loyas Joyce Lanyon
Russell Hoptonas Terry Wickett