Join Pulitzer Prize-Winning Professor Elizabeth Fenn, chair of history, for a talk about the great smallpox epidemic of 1775-82 and an interactive discussion about the impact of infectious disease, past and present. Fenn's books Pox Americana and Encounters at the Heart of the World will be available for purchase. Part of the proceeds will benefit the Buff Bicycle Classic Scholarship Fund. CU on the Weekend is free and open to the public. Saturday, Oct. 31, 1 to 3 p.m., Jennie Smoly Caruthers Biotechnology Building, Butcher Auditorium.