"It was the potato salad at the church picnic that poisoned half the people”. Every public health student has heard this example in school I’m sure. It’s the classic case of a single, ready to eat food item served to a group of people who may have eaten it, along with other food. The example goes on to explain how we calculate attack rates and discover the contaminated item that sickened the people. Sounds like the game Clue. Investigating foodborne illnesses is very much a detective game. The investigation as to who, what, when, and where all need answers to determine the source of contamination. There may be isolated cases of illness, or there may be a larger group of people that have a common link i.e. the holiday party at work. Either way, food can make us sick.