In Walked Mary: Dick Allison comes to the aid of Mary Ann Hubbard, a young, dispossessed woman in the South, and the two become close friends. Dick leaves the South to move to New York, and Mary soon finds herself in dire financial straits. She decides to ask her friend Dick in New York for help, and travels there to see him. Unfortunately, she arrives at Dick's place on the evening of his bachelor party, but Dick persuades his fiancée, Betsy Caldwell, to put up Mary for the night. Mary soon finds out something about Betsy that Dick does not know.