This activity describes a simulated epidemic using the nontoxic, noninfectious, fluorescent agent GloGerm. Students rub gauze saturated with mineral oil on a gloved hand; one student in the class has oil containing GloGerm. The students then proceed through 3 to 5 controlled rounds of handshaking, recording each "encounter." After the last round of handshakes, the spread of the epidemic is traced by recording the "infected" glowing hands, detectable by ultraviolet light. The students share and analyze the data from the rounds of handshakes and trace the transmission of the agent, GloGerm, back to patient zero.