In a sharp tightening of the diplomatic screws, the director-general of the World Health Organization (WHO), Tedros Adhanom Ghebreyesus, is urging China to increase its transparency about the early days of the COVID-19 pandemic and allow greater access to its labs to help resolve the origin of SARS-CoV-2. Tedros also says WHO will create a new body to conduct the next phase of studies into the emergence of the virus, an unexpected move that concerns some scientists, including at least one member of an existing mission the agency organized to study COVID-19's origin. Tedros called for more aggressively probing the two leading theories of how SARS-CoV-2 first infected humans and then emerged in Wuhan, China, in December 2019: that the virus made a natural "zoonotic" jump from an unknown animal species into humans or, more controversially, that it first infected a human during laboratory or field studies of coronaviruses found in animals. (An even more contentious theory suggests the virus was genetically engineered in a Wuhan lab.)