In 1857, Mary McLean leaves her sweetheart in the Scottish Highlands to teach school in India, where her father is a missionary. In India, the new Sepoy leader, Nana Sahib, sends his agent Azimooah to appeal to Queen Victoria to restore the pension given during his father's reign, but the Queen refuses because Nana Sahib is an adopted son. The infuriated Sepoys attack an English town and capture Mary and her father. After Nana Sahib adds Mary to his harem, she pretends to like him to learn information about his plans, which she passes on to British officers when she escapes.