Considered the black sheep of the Mackenzie family, Cam, born in 1846, is heir to the dukedom while Hart is childless. He is a wizard with horses--he breeds, raises, and trains prize racehorses. His advice on horseflesh is sought by everyone in England and Scotland, including Queen Victoria, for whom he makes purchases.

Cameron meets and marries the scandalous Lady Elizabeth Cavendish in 1865—she was reputed to have run away to be an actress in Paris and possibly was the mistress of the Prince of Wales. She bears Cameron a son—Daniel—then dies in mysterious circumstances. Cam blames himself for his wife’s death, and there are those who whisper that he killed her.

Born in 1851, Mac is the red-haired, wild younger brother comfortable in the knowledge that there are several heirs between him and the dukedom. He ran away at sixteen to study art in the back streets of Paris, learning from such famous artists as Edouard Manet and Edgar Degas.

Mac is a brilliant painter but doesn’t sell his work—he gives it away or donates it, and has set up trust funds to help struggling artists. Before his marriage he had affairs with all his female models (claiming that this made them better at keeping still for painting). After his marriage, Mac only had eyes for his wife 

In 1875, Mac meets and falls in love with Lady Isabella Scranton, daughter of the very straight-laced, blue-blooded, Earl Scranton. Mac persuades Isabella to elope with him the night of her debut ball. Isabella, only eighteen, lets herself be swept away. But the marriage proves difficult (with numerous problems), and they separate three years later. Isabella remains friends with the rest of the Mackenzie brothers, but Mac and Isabella never speak.

Born in 1854, Ian has been considered “mad” for most of his life: he’s quiet, almost broody, then will break out with some extraordinarily brilliant thought.

In 1864, when Ian was ten, Ian’s father had him committed to a private asylum and labeled mad. Because of Ian’s ability to learn but inability to meet another person’s gaze, he was considered sullen and arrogant. The doctors subject Ian to numerous experimental “cures,” which Hart tried to stop but was unable to.

Hart releases Ian the day Hart inherits the dukedom and brings him home. Ian takes time to re-assimilate to life. He finds relief in obsessively collecting Ming bowls and by visiting courtesans, who view Ian as charming and generous.

Ian looks out for the weak because he learned in the asylum that what the meek mostly inherit is beatings. Hart uses him as a kind of human recorder, and Ian lets him in gratitude for Hart helping him. Ian is lonely and knows he’ll never be “normal,” but realizes he’s lucky to have the unruly Mackenzies as brothers.