Almost every year, I make a pilgrimage to a little town on Lake Huron in northeast Michigan, where my family has vacationed since my mother was a child. Not far from the quaint, two-block downtown, with its ice cream parlors and tourist clothing shops, sits an old lighthouse marked with a terribly sad plaque. The plaque tells the story of Blanche Deckett, the daughter of a lighthouse keeper, who died a century ago during the influenza pandemic.