Fighting the Laws That Fail Families : CROWS OVER A WHEATFIELD by Paula Sharp; Hyperion; $22.95, 448 pages

“The law is a miraculous water that flows upwards, that seeks the high places, the craggy pools where power collects,” the narrator of Paula Sharp’s new novel--a federal judge, no less--says in anger and despair at the inability of the law to protect the powerless: abused women and children.

Make no mistake: “Crows Over a Wheatfield,” titled after a scene Vincent van Gogh painted in his madness, is a protest novel. Like Upton Sinclair’s “The Jungle” or Frank Norris’ “The Octopus,” it tells an emotional story to make us reach an intellectual conclusion: The Chicago stockyards are filthy and unsafe; Southern Pacific Railroad is an oppressive monopoly; in this case, family law in the United States is flawed almost beyond repair.

Not just individual laws or the people who administer them--though Sharp, a practicing lawyer as well as the author of two previous novels, “The Woman Who Was Not All There” and “Lost in Jersey City,” and a short-story collection, “The Imposter,” has plenty of harsh words for both.

No, what offends Sharp is the law itself: its devious complexity, its brute, invasive force. “The devil is the law,” says her heroine, Mildred Steck, who organizes an “underground railroad” for victims of domestic abuse after the law has compelled her to deliver her terrified 3-year-old son, Ben, for visits to a husband she knows to be a sociopath and a sadist.

And the narrator, Melanie Ratleer, knows from experience how the law is a tool that all too neatly fits the hands of wealthy, egotistical and manipulative men--such as her father, Joel, a brilliant lawyer who specialized in bamboozling juries to free the guilty while he tyrannized over his family.

This ordeal has left Ratleer a joyless grind, blindly following her father’s profession in New York. It has stifled her stepmother, Ottilie, and half-crushed her brother, Matt, who became psychotic after taking LSD as a teenager.

Hope appears only when Ratleer revisits her native Wisconsin and finds Ottilie, now divorced, recovering her spirits. Matt is living in a halfway house run by Mildred Steck’s father, a kindly minister who aids undocumented Central American refugees as well as the mentally ill.

It seems to be a sanctuary from force and fraud--until Steck’s husband, Daniel, returns from a research trip to Brazil. He charms everyone at first, only gradually revealing himself to be a chameleon, capable of expressing compassion convincingly--to a court-appointed psychiatrist, for example--but incapable of feeling it.

This central section of the novel is the best. Sharp has taken the time to develop her characters and the rural Wisconsin setting thoroughly; now, as Daniel’s courtroom machinations threaten not only his wife and child but Matt as well, she gives us scenes of heartbreaking suspense--Ratleer, on Steck’s behalf, waiting in a freezing car in a futile attempt to stand guard outside the house where Daniel has little Ben at his mercy three days a week.

Never mind that the story is a string of worst-case scenarios; the law sometimes does pixilate the truth rather than clarify it, and Sharp’s description of how this can happen is plausible. Never mind that Daniel, like Joel, is demonized; in real life, too, evil acts and their perpetrators are not always easy to explain in human terms.

No wonder Steck kidnaps her son and disappears.

But then the story jumps ahead 15 years, to another spouse-abuse case and a standoff between the FBI and a would-be bomber, and Sharp must pay the price for choosing Ratleer as narrator. Her dilemma--should she give up the law?--isn’t as exciting as the people and the conflicts in the middle of the book.

They return at the end, as Steck surfaces from the underground, but meanwhile the emotional side of “Crows Over a Wheatfield” has weakened enough to let us question the intellectual side--not what the author of a protest novel wants to happen.

The law may be a mess, but what do we put in its place? Can society rely for justice on clandestine networks of anarchistic computer hackers and keepers of safe houses just because--unlike other “outlaws,” such as the anti-abortion militants and “freemen” types who lurk at the edges of the story--these are supposed to be the good guys?

Steck’s answer is ringing but not sufficient: “There’s a whole nation of women out there . . . who live in terror, trapped and dependent, with . . . children, and the law won’t free them.”