As a rule, when nice people go mad in polite Victorian fiction, their relatives discreetly remove them from society and lock them away in the attic. But a perfectly nice young man named Louis Trevelyan flies in the face of that literary convention in Anthony Trollope's 1869 novel, He Knew He Was Right. Not only does Louis have a very public breakdown, but he also succeeds in putting the blame on his innocent wife.

"It's a dark book, a bit shocking, really," said Andrew Davies, who adapted the novel for a two-part "Masterpiece Theater" presentation, co-produced by the BBC and WGBH Boston, that begins tonight at 9 on KCET/Channel 28.

"This is the only one of Trollope's novels I've come across that deals with pathological behavior," Davies said, pointing out that the author took his inspiration for Louis' tragedy -- his insane jealousy of his virtuous wife -- directly from Shakespeare's "Othello."

In Trollope's treatment, Louis Trevelyan (played by Oliver Dimsdale) visits the Mandarin Islands, falls in love with the governor's high-spirited and permissively educated daughter, Emily (Laura Fraser), and brings her back to London as his wife. Their idyllic marriage produces a son and is the envy of society -- until Emily naively indulges the attentions of her godfather, Colonel Osborne (Bill Nighy), a notorious rake who maliciously encourages rumors of an affair.

Emily remains a free spirit

Stung by the gossip, Louis attempts to lay down the law to his wife, but Emily will not allow her husband to curb her freedom, idealistically insisting on his trust in her virtue. Unfortunately, the worm of doubt has infected Louis' brain. He hires a private detective to follow Emily and, in a fit of delusional jealousy, turns her out of the house and sets in motion the ruinous events to come.

This "edgy, dark, offbeat kind of novel," said Davies, is quite different from classic Trollope works like "The Warden" and "Barchester Towers," which are set in country parsonages and cathedral closes and offer a "comfortable view of the world" inhabited by Machiavellian bishops and impoverished prelates. To the screenwriter, who also adapted Trollope's 1875 satiric broadside, The Way We Live Now, for a 2002 "Masterpiece Theater" production, "He Knew He Was Right" is a work that "feels startlingly modern," not only for its frank depiction of sexual jealousy and the ruination of a marriage but also for its portrayal of forthright, independent women.

"The story is very much about confident women who are discovering themselves and asserting themselves as strong personalities," Davies said. "The men either succeed or fail in coping with female independence and female sexuality."

With her indulgent upbringing, Emily is already independent to the point of folly, and her refusal to placate her husband quickens the tragedy. But Trollope also populates the multiple subplots of his story with strong-willed women who make shrewd use of the power of their sex to achieve their objectives. Less naive than the heroine, they draw on whatever resources are available to them -- beauty, brains, money, social status, political connections, a nice piece of property -- and Trollope clearly admires their tactics.

"It is quite a galaxy of mothers and daughters -- and written by a man!" said Geraldine James, who plays Emily's mother, Lady Rowley, a charming and resourceful matriarch whom the actress describes as "not manipulative, not underhanded, not secretive -- just clever, extremely clever, in a subtle way."

Marveling at Trollope's understanding of such a woman, James researched the novelist's background and discovered that his mother, Frances Trollope, was the successful author of about 40 books, including some controversial anticlerical novels. "She was a very strong woman and an important writer of her time," James said. "The child of such a mother will often rebel, but it sounds as if Trollope had a very positive relationship with his mother and liked strong women."

Young and old, the women Trollope draws in He Knew He Was Right certainly have forceful personalities and minds of their own. Emily's younger sister, Nora (Christina Cole), rejects a wealthy, aristocratic suitor for the penniless journalist Hugh Stanbury (Stephen Campbell Moore). Hugh's younger sister, Dorothy (Caroline Martin), turns down the marriage proposal of the Reverend Gibson (David Tennant), the country vicar chosen for her by the rich maiden aunt (Anna Massey) on whose whims of generosity the family depends. And in a comic twist on these matrimonial complications, Arabella French (Fenella Woolgar), who loves the spineless Gibson, devises an ingenious scheme for stealing him away from her own sister, Camilla (Claudie Blakley).

"Bella wins -- hooray!" cheers Woolgar. "She's manipulative and scheming, but in those days and in that society, marriage was the only option for women. It just goes to show how few opportunities were open to a woman like Bella that she would even scheme against her own sister." While the actress took delight in her comic role, it distressed her to think about the "total powerlessness" of young women whose circumstances made them unmarriageable.

And old maids at 26. "I think there's an absolute desperation to these women," Woolgar said. "It's really sad. It's tragic. If Bella had good looks or a lot of money, she could have any man she wants. But her father's dead, and her people are not rich. So, not having looks or, more importantly, money, she's got to use whatever power she has -- and she's got some brains on her, has Arabella -- in a more underhanded way."

Eccentric aunt speaks her mind

If money is power, then Jemima Stanbury, the eccentric aunt who controls the Stanbury family fortune, should be one of the most formidable figures in the story. Indeed, she speaks her mind and orders her relatives about without fear of contradiction. But as Anna Massey points out about the reclusive old woman she plays in the drama, her true power derives not from her money but from strength of character. "She has an incredible energy, an energy of mind and of body," Massey said. "No tight corsets for Aunt Stanbury -- she's a woman of action."

And while this bossy old biddy does try to organize people's lives for them, she has the courtesy and courage to admit when she's made a mistake and gone too far. "What makes Aunt Stanbury extraordinary, for her own or any other period, is her absolute honesty," Massey said. "Anyone who can acknowledge her own faults is not truly terrifying. It's the bigots and the hypocrites of the world who are genuinely frightening."

Unlike Aunt Stanbury, Louis Trevelyan can't bring himself to admit to his mistakes. And unlike Dorothy and Nora and other young women in the story who defy social convention to choose their own husbands, Louis lacks the courage to stand by his own unorthodox mate.

"It's a pity, really," said Davies. "Louis goes halfway across the world to find a woman who has been unspoilt by the corruptive influences of London society, the way that Englishmen today go to places like Thailand to find brides. And then when he finds someone brought up to think independently, she's a bit too much for him -- almost terrifying."

Davies went on to suggest that despite the pathology of Louis' behavior, Trollope was writing about his own ambivalence about modern women. "These fiery women with strong opinions who'd argue like a man were enormously attractive to him, if also a bit daunting," he said, noting that on Trollope's travels to America he fell in platonic love with "a very vivacious, assertively feminist" young woman named Kate Field. There's a version of her in the drama in the poised and self- confident American heiress who snaps up Nora's rejected suitor and charms him with her strong political opinions.

"Trollope was extremely stimulated by such women," Davies said, "but as they became more assertive, he experienced some doubts about the relationship between the sexes. So he pushed these fears and anxieties to their logical conclusion and projected them onto Louis, who is completely destroyed by them. Poor chap."Airs tonight

"He Knew He Was Right" airs at 9 tonight on KCET/Channel 28 as part of "Masterpiece Theater." It's based on Anthony Trollope's 1869 novel of the same name about a man (Oliver Dimsdale as Louis Trevelyan) who is so insanely jealous of his wife (Laura Fraser as Emily) that he goes mad.