Mary loves her husband Major Ochterlony, and their marriage is happy - except when the fidgety Major periodically becomes obsessed with some unwelcome idea which he insists on seeing through, no matter how foolish or hurtful to Mary. They are in India, far from home, when he has his worst idea yet - that they must remarry, as he fears that their earlier "Scotch marriage" could be difficult to prove. This action brings gossip and shame on Mary, and has even more serious repercussions after Mary is widowed and back in England. The last volume of the novel is suspenseful, as the remarriage is brought against Mary in a way she never envisioned. Other story lines include a love story and a story of selfish passion.