Dennis Lehane has extraordinary books to his credit: "Mystic River" and "Gone, Baby, Gone" among them. But nothing he's written before -- not a single thing -- prepared me for "The Given Day."

It is a novel of epic proportions and yet compelling reading for each of its 700-plus pages. It is a historical novel that smacks of today's politics. And it is Literature (with a capital L) disguised in potboiler clothing.

The story is set in 1918 Boston. The War to End All Wars is near an end. Race riots in several American cities, labor unrest and an influx of Bolsheviks have put the nation at a crossroads. By telling the story from the perspective of two very different individuals, Lehane brings a crucial era in the country's past vividly to life.

Danny Coughlin is a beat cop with a Triple Crown pedigree. He's Irish. His father, Thomas, is a departmental captain. And his godfather, Eddie McKenna, is an influential police lieutenant.

Luther Laurence is a black man with a sad past. Laid off by a munitions company, he falls into bad company, sells drugs and then does something worse. The conventional wisdom is that the two are natural enemies: lion and lamb, black and white, cop and criminal. But they share a sense of helplessness. Both feel like chess pieces trapped on someone else's board; every move they make seems beyond their control. They have more in common with each other than with the forces that control their destinies.

The milieu is similar to today: hysteria about Bolsheviks bringing terrorism and inciting revolution; the powers that be see that in the burgeoning union movement, and they're prepared to fight back.

In a statement that might have come directly from today's paper, Mitchell Palmer, the U.S. attorney general, says: "Ordinary times call for ordinary law. Would you call these times ordinary?"

Coughlin is asked to go undercover to ferret out terrorist leaders, but discovers that most of the people he comes in contact with are ordinary Joes with legitimate grievances. Promised a detective's shield, he spies on fellow cops at union meetings, but becomes sympathetic to the cause. Like them, he earns only 29 cents an hour for a 73-hour week, receives no overtime and must pay for his uniform.

Coughlin's former partner is debilitated by the Spanish flu, which he caught while on duty. But he's fired anyway, with no benefits. What's Coughlin to do? "The question remained, as it had throughout Danny's life, as to what exactly was good. It had something to do with loyalty and it had something to do with the primacy of honor."

Meanwhile, Laurence, who works as a houseman in the Coughlin home, is faced with a Hobson's choice. He lives with a family that helps found the NAACP, and he is attempting to rebuild his life. But McKenna knows about a serious crime Laurence committed before he moved to Boston and wants him to hide guns in the new NAACP headquarters, which McKenna plans to raid.

It is an upside-down universe, where the supposed good guys are not and the only people who have a moral compass are the powerless. The book is filled with dozens of major characters who practically jump off the page. But at its heart, it is a simple tale of two men who want nothing more than to do the right thing.

Curt Schleier is a book critic and author in New Jersey.