It's a bit tricky to categorise The Narrow Road to the Deep North. You'll tend to call it a historical fiction based on its WW11 setting and characters, but it's actually first-rate literary fiction, though at some points it reads like a non-fiction novel.
The Narrow Road to the Deep North is about the horror and survival of seven-hundred POWs trapped in Siam(now Thailand) working for Burma Death Railway during WW 11. As expected you read about lots of atrocities perpetrated on the prisoners by the Japanese Army. There is Colonel Kota who has special affinity for enemy necks and does not only gloat over beheading the enemies, he also teaches this skill with live demonstrations. There is again Major Nakamura who, doped with "shabu", would do anything however brutal for the sake of the Emperor and has no remorse for dragging the sick and emaciated of the prisoners for the hard manual work for the railway, and thrashing and killing them on the slightest pretext.
The prisoners have a hell of a time with their back-breaking labour, little inadequate food, lack of hygiene and sanitation in their barracks, and many of them being attacked with deadly diseases like cholera, malaria, beriberi and so on. Still amid them you see interesting characters like Darky Gardiner the ever-helpful sergeant, Rabit Hendricks the artist, and Jimmy Bigelow who plays bugle. But most interesting of them is Major Dorrigo Evans, a doctor by training, who has been in charge of the unit and has a genuine feel for his soldiers and rushes to protect them in whatever ways, an altruist character, and always takes the heat from the Japanese.
It's a poignant narrative, but I liked the novel for a separate reason: for its wave of humanity that flows through its pages. None of the characters are depicted in black and white. Flanagan adds the gray shade to all of his characters to do them justice and feel them like human.
Oddly, however, the novelist follows his characters - Colonel Kota included - till their death. It feels kind of superfluous and would be better left to readers' imagination. This is where the novel reads like a non-fiction.
Nevertheless, I enjoyed the novel. Richard Flanagan is a real writer.
I strongly recommend it.