Lewis Grantley is left an orphan in a foreign country at seventeen. As a son of English parents, though raised abroad, a fellow countryman, old Sir Patrick Murray, is consulted on the subject, and he unofficially adopts the boy. They become closely attached to each other until the old man’s demise eight years later. To Lewis’s surprise, he is left the sole heir to his benefactor’s fortune, in spite of Sir Patrick’s having close relatives he had long fallen out with. While he is thought by many to be an unprincipled manipulator who has cajoled the old man into making him his heir, he had never paid the subject a thought, and now decides he must do something to deal with this. On learning that Sir Patrick’s closest kin is still living on the Murray estate in Murkley, Scotland, he decides to travel there and offer himself, with his fortune, to the woman who should have been the heiress.
He thus soon becomes a familiar presence in the social circles of the small village of Murkley, under the name of Lewis Murray, so as not to raise suspicions. This way he finds out that Sir Patrick’s kin is not a single woman, but three sisters, Margaret, Jean and Lillias. He mistakenly believes the three to be approximately the same age, all middle aged women, when in fact Lillias is hardly seventeen, the offspring of General Murray’s second marriage. He thus tentatively begins wooing the sister he finds more accessible (in consequence of a common interest in music), Jean, before he meets Lillias and falls in love with her. He still believes himself too compromised with Jean and proposes to her, in spite of the age difference, to be politely refused in memory of her deceased lover. They, however, become as close as mother and son in the knowledge of their shared secret.
Lillias has been overprotected by her sisters, especially by the elder sister, Margaret, who, in her love, thinks the young woman too good for everything and everyone, and thus has planned a magnificent coming-out for her in the London season. This way she also frustrates any schemes local families might have on the marriageable heiress to Murkley (in spite of New Murkley, a grandiose, empty, unfinished mansion Sir Patrick, her grandfather, designed in his youth, being her only real dowry). One such family is the Stormonts. Mrs. Stormont opposes her son Phillip’s relationship with Lillias’ best friend, Katie Seton, the minister’s daughter, unaware that they are secretly engaged. In a slightly comic subplot we see how Phillip reluctantly and futilely follows his mother’s advice, to be rejected by Lillias and thus sent back to Katie.
Not long before they leave for London, Lewis approaches Margaret on the subject of proposing to Lillias. Margaret, furious at what she thinks his impudence in approaching her beloved sister, not only rejects him as suitor but also immediately sets out for London. Having always being confident in the greatness of the Murray family, Margaret realises with dismay they are utterly unknown in London society and that they have virtually no access to most important circles. The turning point comes with a grand ball thrown by the Greek ambassador, to which everyone seems to be invited but them. Lewis, an influential man in the capital, secretly intervenes and manages to get invitations for the Murray sisters, not only to the Greek ball, but also to every event of social importance, where every attention is paid to them. Little does Margaret know that they owe this social acknowledgement to Lewis, believing it to be overdue recognition of their merit. Thus there is a chance for Lewis and Lillias to grow close to each other, and for Margaret to look upon the young man with kinder eyes. Already considering a proposal of marriage, Lewis recruits the family lawyer’s assistance in telling Margaret the truth, that he is the one who inadvertently became the means to disinherit Lillias. Margaret strongly expresses her contempt and hurriedly takes her sisters back to Murkley.
In the meantime, Lillias has fallen in love with the plain and kind Lewis, and wonders at his absence until she learns about his true identity when he legally disowns his fortune in her favour. Margaret would secretly accept such sacrifice on her sister’s behalf, but Lillias would never allow it, and tells her sisters of her feelings for him. They send for the young man in order to settle matters between them, but they find out too late that he has recently accepted a position as secretary to a Governor in the British colonies. When the news reaches him he replies, promising he will be back as soon as his duties allow. After a whole winter of heartbreaking despair waiting for his return, Lillias unexpectedly meets Lewis at New Murkley, and they return together to her sisters and the family estate.