Michael MacCauley, an Irish-American life insurance salesman and former police officer, is a family man with a wife and teen-aged son. He goes through the same routine train commute to work and back every day, taking the Hudson Line from Tarrytown to Grand Central Terminal, often interacting with the same other commuters. His daily routine is interrupted when he is abruptly laid off from his job after a decade at the same company, leading him to wonder how he will pay his mortgage or afford his son's college tuition. On the train home, Michael meets a mysterious woman named Joanna, who makes small talk with him. Joanna describes herself as academic who studies human behavior and tells him there are 16 distinct types of personalities..