Remembering Babylon by David Malouf.
It's the mid-19th century, and we're in north-eastern Australia. Lachlan Beattie and his two cousins Janet and Meg are out playing and exploring along the boundary of their family property when a strange ragged human figure appears and prostrates himself before them, claiming in broken English to be "a British object".
This, it turns out, is Gemmy Fairley, born and brought up in London, former dogsbody at a timber mill and apprentice to the local ratcatcher and later a ship's boy, cast ashore when he contracted some fever that the crew were presumably keen to avoid catching. Taken in by an aboriginal tribe, he spends the next sixteen years living with them and learning their ways before the gradual incursion of the white man into their territory brings back memories of his former life and offers the opportunity of escape.
Gemmy's sudden appearance causes some consternation among the small pioneer community - English-born he may be, but sixteen years of outdoor living have left him browned and weatherbeaten and not much resembling any of the members of a community featuring a high proportion of bluey-white Scots. On top of that, how long do you, as a white man, have to live among savages before some vital spark of civilised humanity is extinguished and you become irredeemably one of them? And don't they have access to some sort of mystical congress with some Great Spirit of the land who can move the very trees and rocks to do his bidding? So what if Gemmy has surrendered himself just so he can be their eyes and ears within the white community? After all, it's not as if anyone asked the blacks' permission to steam in and start cutting down trees and building roads and the like. Maybe they're a bit pissed off about it?
Gemmy himself doesn't participate in any of these discussions, preferring to keep himself to himself and just do odd jobs round the farm owned by Jock McIvor (Lachlan's uncle and Meg and Janet's father) in exchange for bed and board. But this doesn't prevent all the community's irrational fears being projected onto him, or the finger of suspicion being pointed at him when various random mishaps occur, as they inevitably do. So eventually it's decided that it would be best if Gemmy were removed from the heart of the community and went instead to live with old Mrs. Hutchence on the edge of town - she'll be happy to take him in, and everyone already considers her to be a bit batty anyway.
We then leap forward fifty years to the time of the First World War. Janet is a sister in a religious order and Lachlan is a government minister. He comes to visit her partly out of brotherly concern and partly on official business - both he and she have been publically found to have been (entirely innocently) in contact with people of German origin for various reasons during a period of intense public paranoia, something which is probably going to ultimately cost Lachlan his job and Janet a period of unwanted notoriety.
The point of the epilogue, presumably, is to illustrate the universality of the points being made in the main part of the novel - tribalism, xenophobia, general suspicion of outsiders and anyone who seems to be operating according to an even slightly different set of social norms from one's own, be they German or Aboriginal or whatever. The tension with the aboriginals is particularly, well, tense, because of the way in which the European settlers have taken over their lands without much in the way of negotiation. This was a central theme of the previous Malouf novel in this list, The Conversations At Curlow Creek, a similarly slim volume (200 pages or so) that didn't go out of its way to explain itself but left the reader to do a bit of work for himself. I actually think this one is better, for all that Gemmy himself drifts out of the narrative about two-thirds of the way through and we never conclusively find out what happens to him. The point, I suppose, is that the specific details of his fate are not really the point.
The specific plot device of a person of European origin emerging from the Australian bush to attempt to re-integrate themselves into white society (with varying degrees of success) has been a theme featured in a couple of previous novels in this series, notably Strandloper and A Fringe Of Leaves. As in those books the central character here is based on a real person, in this case James Morril.
In addition to being shortlisted for the 1993 Booker Prize (which was eventually won by Paddy Clarke Ha Ha Ha as featured here quite recently) Remembering Babylon won the inaugural International IMPAC Dublin Literary Award in 1996; my list here goes: 1996, 2000, 2002.