The Street Sweeper, By Elliot Perlman

Heed these lessons of history, or else

How did a German cleric come to sing African-American spirituals popularised by the black Civil Rights movement with his seminary students in Nazi Germany? This is one of many human puzzles contained within the sweep of Elliot Perlman's epic third novel, which links two disparate men in contemporary New York in a fascinating web of fiction and fact.

Lamont Williams is an African-American man who was duped into being the getaway driver during an armed robbery. Released from prison, he procures a job as a hospital janitor, where he befriends an elderly patient dying of cancer. Both men are haunted by their pasts: Lamont has a young daughter whom he hasn't seen for years; the patient lives under the cloud of his concentration camp memories.

Across the city, Adam Zignelik, a historian at Columbia, is crisis-ridden. He knows that his lack of new research is going to lose him his job, but he can't find a topic to inspire him – that is, until a suggestion from his boss's father leads him to make a chilling discovery relating to Holocaust survivors.

Weighing in at 550 pages, Perlman's novel may look intimidating, but it's an accessible albeit harrowing read. Perlman has used real history as its basis, drawing on both the racist atrocities which galvanised the US civil rights movement, and on the inhumane crimes of Nazi Germany. Adam's father taught him about the horrific violence that preceded and followed the Brown vs Board of Education case in the US courts which led, eventually, to the end of segregated schools. Adam's boss's father is horrified by a 2007 decision by the Supreme Court to end affirmative action for disadvantaged black kids, and is disgusted by Columbia inviting bigots to speak under the aegis of "freedom of speech". Meanwhile, Adam teaches his students about Dietrich Bonhoeffer, the Nazi-era German Lutheran pastor who drew parallels between the treatment of blacks in the US and that of Jews in his country.

Perlman's novel is no mere re-hashing of history, and although the Holocaust details are devastating, they are not gratuitous. The contemporary characters' concerns, meanwhile, are often those we share – Lamont aches for his child; Adam his girlfriend.

Implausible coincidences occur, and, early on, there are a couple of strained metaphors; a mixed one here ("What happens to human kindness in the belly of a mob ... is it utterly extinguished?"), and an overworked one there ("All the toxic putrefaction that lived in the dark foetid recesses of the bowels of their minds"). But these flaws of over-enthusiasm are trivial in the context of the real events that are brought back to life by Perlman's research. Humans have short memories and our struggles and wars are all disturbingly similar. We need to be reminded of history's atrocities so as not to repeat them.