I cannot create an abstract for the specific article titled "The 'undone science' of opioid overdose deaths" from Science, Volume 391, Number 6784, January 2026, because that article is not included in the search results provided. The results provided include information on related studies from Science from January 2026 that look at the decline in opioid overdose deaths and its link to fentanyl supply disruptions, but are not the full text of the original article you requested to summarize. If you would like, I can create a summary based on the available information from the search results, or if you have access to the full text of the article, I can summarize it according to your requirements.