In her essay ‘This Little Theory Went to Market’ – one of more than thirty pieces included in The Best Australian Science Writing 2024 – Elizabeth Finkel undertakes a pinpoint dissection of the two prevailing theories about the origins of SARS-CoV-2 (Covid-19): ‘natural origin versus a lab leak’. What Finkel is at pains to point out in her essay is that science ‘advances ... on the “weight of evidence”’ and that, based on that weight of evidence, SARS-CoV-2 ‘was made not in the laboratory of man, but in nature’. Finkel’s essay is essential reading not only for her meticulous analysis of the evidence – peer-reviewed papers and US intelligence sources – but also for her approach: ‘I do not blindly trust scientists. My lodestone is the scientific method itself.’