Outside a rural Pennsylvania motel, nine-year-old Lulu smokes a cigarette while sitting on the lap of a trucker. Recent art grad Quinn is passing through town and captures it. The photograph, later titled "Lulu & the Trucker," launches Quinn's career, escalating her from a starving artist to a renowned photographer. In a parallel life, Lulu fights to survive a volatile home, growing up too quickly in an environment wrought with drug abuse and her mother's prostitution. Decades later, when Quinn has a retrospective at the Whitney Museum of Art and "Lulu & the Trucker" has sold at auction for a record-breaking amount, Lulu is surprised to find the troubling image of her young self in the newspaper. She attends an artist talk for the exhibition with one question in mind for Quinn: Why didn't you help me all those years ago? Tell Me One Thing is a portrait of two Americas, examining power, privilege, and the sacrifices one is willing to make to succeed. Traveling through the 1980s to present day, it delves into New York City's free-for-all grittiness while exposing a neglected slice of the struggling rust belt.