Unveiling African swine fever virus African swine fever virus (ASFV) is highly contagious and often lethal. With no vaccine or effective treatment, infections often require large-scale culling of pigs. Wang et al. apply cutting-edge cryo–electron microscopy techniques to determine the structure of this very large DNA virus. An 8.8-angstrom-resolution reconstruction shows the five layers of the virus, and the fourth capsid layer could be reconstructed at 4.8-angstrom resolution. The structure reveals epitopes in the major capsid protein that distinguish ASFV from other nucleocytoplasmic large DNA viruses and shows how the minor capsid proteins stabilize the capsid. Science , this issue p. 640