Cover photograph: Medusavirus is a novel large DNA virus discovered from hot spring water in Japan. The viral proteins are found to be phylogenetically placed at the root of the eukaryotic clades. Based on its unique morphological characteristics (surface view of threedimensional reconstruction of the medusavirus particle, lower right) and phylogenomic relationships (phylogenetic tree of metacaspase genes, upper left) with other known large DNA viruses, medusavirus forms a new family, the Medusaviridae. Background, a Japanese hot spring and medusavirus particles observed by cryo-electron microscopy. (See related article at e02130-18.) (Copyright © 2019 Yoshikawa et al. CC-BY 4.0)