The latest major revelation in this line emerged this week. Taken at face value, it’s extraordinary: Ben Hu, a high-level researcher at the Wuhan Institute of Virology, and two colleagues, Yu Ping and Zhu Yan, could have been the first people on the planet to be infected with SARS-CoV-2, according to anonymous sources cited first in the newsletter Public and then in The Wall Street Journal. These proposed patient SARS-CoV-zeros aren’t merely employees of the virology institute; they’re central figures in the very sort of research that lab-leak investigators have been scrutinizing since the start of the pandemic. Their names appear on crucial papers related to the discovery of new, SARS-related coronaviruses in bats, and subsequent experimentation on those viruses.

Is this the “smoking gun,” at last, as many now insist? Has the Case of the Missing COVID Origin finally been solved? Hu and Yu each denied the allegations in emails to Science, saying they did not get sick in autumn 2019. “My colleagues and I tested for SARS-CoV-2 antibody in early March 2020 and we were all negative,” Hu wrote. But those denials notwithstanding, if these researchers did turn out to be the very first infected people, then their professional activities would mean they almost certainly caught the virus in the lab, not a market stall full of marmots and raccoon dogs. The origins debate has from the start revolved around a pair of dueling “coincidences.” The fact that the pandemic just happened to take off at a wet market suggests that the virus spilled over into humans from animals for sale there. But the fact that it also just happened to take off not too far away from one of the world’s leading bat-coronavirus labs suggests the opposite. This week’s information seems to tip the balance very heavily toward the latter interpretation.

The only problem is, we don’t know whether the latest revelations can be trusted, or to what extent. The newly reported facts appear to stem from a single item of intelligence, furnished by a foreign source, that has bounced around inside the U.S. government since sometime in 2020. Over the past two and a half years, the full description of the sickened workers in Wuhan has been revealed with excruciating slowness, in sedimenting clauses, through well-timed leaks. This glacial striptease has finally reached its end, but is the underlying information even true? Until that question can be answered (which could be never), the origins debate will be stuck exactly where it’s been for many months: always moving forward, never quite arriving.

The story of these sickened workers has been in the public domain, one way or another, since the start of 2021. Officials in the Trump administration’s State Department, reportedly determined to go public with their findings, put out a fact sheet about various events and circumstances at the Wuhan Institute of Virology around the beginning of the pandemic. Included was a quick description of alleged illnesses among the staff. The fact sheet didn’t name the sickened scientists or what they did inside the lab, or when exactly their illnesses occurred. It didn’t specify their symptoms, nor did it say how many scientists had gotten sick.