Mary Barton is beautiful but has been born poor. Her father fights for the rights of his fellow workers, but Mary wants to make a better life for them both. She rashly decides to reject her lover Jem, a struggling engineer, in the hope of marrying the rich mill-owner's son Henry Carson and securing a safe future.
But when Henry is shot down in the street and Jem becomes the main suspect, Mary finds herself hopelessly torn between them. She also discovers an unpleasant truth - one that could bring tragedy upon everyone, and threatens to destroy her.