I had a moment of recognition when I read that Joan and Colin Diver, the Harvard-educated gentrifiers in Common Ground, moved to the South End and helped create a model school for integrated education. I had also joined a group of progressive parents and educators who created a public school in the Bronx that mixed children by race in every grade. Both my children attended. An endgame seemed possible.

I realize now that I read Common Ground far too quickly nearly 30 years ago, and possibly for the wrong reasons. Common Ground is not the kind of book that can be sifted for quick truths. Lukas resists the typical critic’s insistence that works of social-policy journalism must come complete with a checklist of pat solutions. Any understanding that emerges from his book, he once said, should “seep out through the interstices of the three families.”

It demands a more measured, patient reader. Given this second chance, I understood more clearly how his technique serves his purpose. Lukas tips us off on page one that Common Ground will be full of surprises. He defies expectations by providing no prologue, no roadmap laying out the book’s themes and motivations. Instead, he launches right into the story, almost daring readers to hitch along for the journey.

We might expect the book to open with one of the explosive riots that were synonymous in the public’s mind with Boston and busing. Instead, it begins with a quiet Cambridge scene inside the study of Colin Diver. He is contemplating his future after he graduates from Harvard Law School. This is the opening sentence: “Sunlight struck the gnarled limbs outside his window, casting a thicket of light and shadow on the white clapboards.”

It’s cinematic, in a gently menacing way. But it hardly signals the provocative book we are about to read. I worried for a brief moment that Lukas had chosen a pipe-smoking good-government voice to stand in for the author as the book’s wise and whitewashed narrator. But within a few pages we were deep into the assassination of Martin Luther King Jr. and hurtling headlong into the startling findings of the Kerner Commission report:

Our nation is moving toward two societies, one black, one white—separate and unequal. . . . What white Americans have never fully understood—but what the Negro can never forget—is that white society is deeply implicated in the ghetto. White institutions created it, white institutions maintain it, white society condones it.

It’s vintage Lukas, circling around his subject, tugging at myriad narrative threads, and then swooping in for the kill, all the while painting a portrait of Boston, capturing its mood, its hostilities, its ethnic eccentricities, its politics and power structures, as well as its schools.

Then, in quick succession, each of the other two families is corralled into the same metaphorical space: the moment they all learned of Dr. King’s assassination. Rachel Twymon, a black mother originally from Roxbury, was carefully chosen to represent the presumed benefactors of busing; Alice McGoff was the working-class, Irish-Catholic resister. Add Diver and you have a classic formula that is particularly suited to policy nonfiction: anchoring a sprawling narrative in the lives of three—always three—ordinary people. If Lukas did not invent the model, then he certainly perfected it.

Social-justice journalism has many perils, most prominent among them the reporter’s inclination to line up villains and saints, and cast judgments accordingly. Where the writer’s sympathies lie is rarely a mystery. Lukas’ gift is that he never tips his hand and yet never loses his moral footing. Everyone knows how a Harvard-educated liberal from an upper-middle-class family is expected to react to nativist race baiting, or to a mob of teens spearing a random black pedestrian with an American flag. Yet Lukas manages to step into all his subjects’ lives armed with wisdom, never judgment, and never sacrificing a sharp analytic focus.

In fact, he is at his best when faced with untangling the contradictions of his characters and institutions. In his hands, Louise Day Hicks, the white-gloved “two-toilet Irish” School Committee chairwoman, is both the Bull Connor of Boston and the Lady Bountiful. The “Powder Keg” activists of Charlestown are either mavericks or mindless rioters. In my favorite section he turns his lens on The Boston Globe, accusing it of playing it safe with its busing coverage in a misguided attempt not to offend anyone. The veiled implication is that its anodyne coverage was a calculated attempt to win the Pulitzer Prize, which the paper eventually did—and Lukas did as well, for Common Ground.

LynNell Hancock is the H. Gordon Garbedian Professor of Journalism at Columbia, and director of the school's Spencer Fellowship in Education Journalism.