Learning scientists have created and used virtual worlds to support players’ historical, scientific, and ecological inquiries. Much less explored has been the impact of community events on players’ investigations in virtual worlds. The authors present here the case of a community event Whypox, a virtual epidemic whose annual outbreak in Whyville affects players’ communication and appearance. The authors analyze the different levels of participation ranging from casual to systematic in which players searched out more information about the Whypox, participated in online discussions about its causes and investigated different scenarios with simulations. The discussion examines ethical concerns, the contributions of our findings for the design of such community events, and educational resources in virtual worlds to support informal learning.