Indiana is the story's heroine, a young noblewoman descended from French colonial settlers from Île Bourbon (now Réunion) and currently living in France.

Indiana is married to an older ex-army officer named Colonel Delmare and suffers from a variety of unknown illnesses, presumably due to the lack of passion in her life.

Indiana escapes the house to faithfully present herself in Raymon's apartments in the middle of the night, expecting him to accept her as his mistress in spite of society's inevitable condemnation.

The stoic and remote Sir Ralph, whom Indiana has always seen as an "égoiste", suddenly comes to rescue her and tell her that Colonel Delmare has died from a fever.

At the end of the novel comes a conclusion, a young adventurer's account of finding a man and woman, Ralph and Indiana, living on an isolated farm on the Island.

Indiana cannot leave her husband, Colonel Delmare, because she lacks the protection of the law: under the Napoleonic Code, women could not obtain property, claim ownership of their children, or divorce.