On March 16, 1986, in Pikeville, Georgia, 15-year-old Samantha (Sam) Quinn and her younger sister, 13-year-old Charlotte (Charlie), are at home. They and their parents live temporarily in an old farmhouse, nicknamed the HP, after their family home was burned down in an act of arson. Their father, Rusty, is a criminal defense lawyer for the state, known for defending those accused of the most serious violent and sexual crimes. Rusty attracts negative attention because of his work and the police believe the arson was committed for this reason.

The girls’ mother, Harriet or “Gamma,” has a genius-level IQ and two PhDs; she was given the nickname for her work with gamma rays. She gave up her career to come to Pikeville to care for her aging parents and then be a stay-at-home mom. As Gamma prepares dinner, Rusty calls from the courthouse to say that the sheriff is sending a patrol car over for the family’s safety; one of Rusty’s defendants was acquitted that day, resulting in public outcry. That evening, Gamma unexpectedly hugs Sam in the bathroom and tells her to always watch out for Charlie. Gamma and Sam tend to align with each other, while gregarious and emotional Rusty and Charlie band together.