A man goes to a birthday party, sits next to someone with hantavirus, catches it, gives it to his wife, and dies. His wife then infects 10 more people at his wake. Another guest at that same birthday party has no interaction with the index patient except to say “hello” as they cross paths, but that person gets sick too. One index patient, 33 subsequent infections, 11 deaths, four waves of transmission. This is from a meticulously documented hantavirus outbreak in Argentina in late 2018 and