McKnight answers these questions in just over two hundred dense pages by adding history to his field-trip snapshots. In 1966 he met old people who remembered the days before the whitefellas’ arrival. He met their children: men and women raised in the mission dormitory, doing seasonal work on mainland cattle stations, and increasingly ready, with missionary backing, to defy the authority of the elders and to marry the ‘whitefella way’ – for love, not the integrity of kinship relations. His last trip exposes a society caught in a downward spiral to destruction.

We might want to elevate the Mornington Island story into a parable of colonisation, but McKnight abhors generalisation. He is also suspicious of theory. Instead, we are given slabs of his material ‘raw’: outlines of marriage and sorcery battles; extracts from field notes; passages from missionaries’ journals; then pages of tabulations. Initially, this strenuous empiricism is wearying. Then it becomes enthralling, as themes quietly declare themselves, and we begin to experience the small jolting recognitions that mean we might be beginning to understand these people and what they do. For example, ‘sorcery’ looks less esoteric and more like therapy for helpless anger – gossip pursued by other means. When every death save those of the very old and the very young is judged ‘unnatural’, each death must provoke the question: who had reason to want this? Social life being what it is, there was no shortage of candidates. But while one man might discreetly boast of his power to ‘sing’ his enemies, his sceptical neighbours might ignore him and favour another candidate. Crucially, every death required a ‘square-up’: emotionally charged occasions where suspicions and antagonisms were aired, pursued or collapsed into a weeping heap of shared lamentation. Thus personal tensions were transformed into social events and opened to social mediation.

The violence theme had announced itself, violently, on McKnight’s first field trip, when wild brawls would erupt unpredictably. Mornington Island was rich in food resources. Its Presbyterian missionaries, arriving in 1914, were unusually sensible and sufficiently formidable to keep more predatory whites out. In time, the Lardil had to share their island with refugees from the mainland and neighbouring islands, but their dominance was never challenged, and, sharing language, culture and a vivid sense of kinship, their society remained unusually intact. The people hunted, fished and danced together; McKnight found them ‘kind and compassionate with a rich sense of humour’. Yet ‘fighting seemed the main social activity’, typically beginning with loud statements of grievance, then one-to-one duels. Then kin and supporters came running, and the anxious anthropologist would be caught up in a general mêlée. Deaths were rare: only prescribed weapons were used. But real injuries were sustained. Why did Mornington Islanders fight so often and so hard?

McKnight decided the main reason was the tension generated by ‘sedentarisation’. People who had moved over their land in small bands, meeting only by agreement and for ceremony, were now living cheek by jowl. Once-manageable, even gratifying reciprocal obligations had become painfully onerous. McKnight named this phenomenon ‘relational density’, and it is, I think, an important insight into a little-understood consequence of the settling, forced or unforced, of sophisticated kin-based nomadic societies.

The most radical changes came in the 1970s, with the termination of mainland employment after the equal pay award, and with the implementation of what pretended to be a ‘rights’ agenda: the replacement of the mission by a Shire Council; the addition of unemployment relief to social welfare; and, fatally, the establishment of a ‘wet’ canteen. Island stockmen had always drunk part of their wages in end-of-season booze-ups, but they had done their drinking on the mainland. Now they would drink at home. The orchestrated fighting of the 1960s gave way to drunken brawls and unprovoked assaults, most often on women. With so many homicides, suicides and alcohol-induced deaths, the ‘sorcery’ hypothesis lost emotional traction. The elders no longer have any authority. Young people marry as they choose; residual social power has migrated to white administrators. Now, in McKnight’s final words: ‘like good European Australians the Mornington Islanders are mainly concerned about money, particularly money for beer and in their drunken state they have no idea what they are fighting about.’

In these four works, we have a detailed history of one of the few Australian Aboriginal societies to preserve its territorial integrity and its language from first contact to the crippled present. They constitute a requiem for an inventive, resilient people destroyed by alcohol and the blundering interventions of uncomprehending whites.

There are pleasures along the bleak way. Anthropologists are famously cantankerous; McKnight, born in 1935, is gloriously acerbic. But the reader’s deepest pleasure derives from the eternal anthropological romance: the stranger McKnight’s commitment to the people of Mornington Island, whom he loved, grieves for, but no longer understands.