Trollope's cozy, familiar, gossipy voice addresses the reader directly as he alternately sympathizes with or skewers the foibles of his heroes and heroines. In The Eustace Diamonds, he makes a case for his heroine being the very good and rather prosaic Lucy Morris, a poor young governess who is in love with an ambitious young man, a barrister and member of Parliament, Frank Greystock. But as one may guess from the title, the real "heroine" is Lizzie Eustace, a very beautiful and clever young woman, widowed fortuitously by Sir Florian Eustace, who makes her a very generous will.
Lizzie is grasping, duplicitous, mean-spirited, and narcissistic, but she gets a lot further than others would because she is also rich, young, and beautiful. The diamonds of the title are the crown jewels of the Eustace family, and when Sir Florian dies, rather than give them back up to the family to be kept in trust for her own son, Lizzie refuses, claiming that her husband gave them to her as a personal gift, which is only one of the many lies she tells. This gets the solicitors to planning lawsuits, which makes Lizzie even more obstinate and leads to a great many ridiculous measures to keep them out of anyone's hands but her own.
The plot turns on the battle between Lizzie and nearly everyone else -- her alienated family, the lawyers, and even her betrothed, the weak-willed Lord Fawn. She is a deliciously terrible creation, what these days we would simply call a sociopath. Lying is as natural to her as breathing. She feels very ill-used while amorally pursuing her own desires. I've often wondered how some people can go so blithely through life exactly as Lizzie does with no sense of conscience. Trollope offers a window into these types -- creatures so entirely consumed with themselves that they have no thoughts left over to empathize with others. He sympathizes, tongue in cheek, with his heroine:
Poor Lizzie! The world, in judging people who are false and bad and selfish and prosperous to outward appearances, is apt to be hard upon them, and to forget the punishments which generally accompany such faults. Lizzie Eustace was very false and bad and selfish -- and, we may say, very prosperous also; but in the midst of all she was thoroughly uncomfortable. She was never at ease. There was no green spot in her life with which she could be contented. ["Ianthe's Soul," The Eustace Diamonds]As always, Trollope's cavalcade of characters are well-developed and his prose is always light and witty. The one point of discomfort is the rather startling anti-semitic descriptions of all the Jewish characters, who are all dispatched in the broadest negative and corrosive stereotypes. I haven't read anything about his views, but judging from this example, he was no progressive, contrasting starkly with fellow Victorian, George Eliot, who was far more fair and sympathetic.