The story opens on the day that Ridgeon, a prominent research doctor, is knighted. His friends gather to congratulate him. The friends include Sir Patrick, a distinguished old physician; Walpole, an aggressive surgeon; Sir Ralph Bloomfield Bonington, a charismatic society doctor; and Blenkinsop, a threadbare but honest government doctor. Each one has his favorite theory of illness and method of cure. These are incompatible--one man's cure is another man's poison. Nonetheless, they all get along.

A young woman (Mrs. Dubechat) desperately seeks help for her husband from Ridgeon, who has evidently found a way to cure consumption by "stimulating the phagocytes." Ridgeon initially refuses, but changes his mind for two reasons--Dubechat is a fine artist and Ridgeon is smitten with his wife.

When the doctors meet Dubechat, however, they find that he is a dishonest scoundrel. Ridgeon eventually decides to treat Blenkinsop (who also has consumption) and refer the artist to Bloomfield Bonington, this insuring that he will die. In the end Ridgeon justifies his behavior as a plan to let Dubechat die before his wife find out what an amoral cad he actually was. This, in fact, happens and Dubechat's artistic reputation soars.