A Scarlet Letter explores the stigma surrounding the word "atheist," a word often associated with immorality, anger, and... devil-worship? Yet, despite its stigma, nonbelief is the fastest growing "religious" segment in the American public. This documentary explores why atheists are choosing to stand out against religious intrusion in public life while showing the human face of atheism. It examines the question of why so many people are passionate about a negative.