Abigail and Brittany Hensel are conjoined twins, two separate people with one shared body, two arms and two legs between them. Born in 1990 and raised in a small Minnesota community, they grew up shielded from outside attention while their family treated them as ordinary kids with distinct personalities, tastes, and disagreements. The film shows them doing the things any teenager does, playing piano, riding a bike, swimming, playing softball, each girl controlling her own side of the body while somehow moving in sync. Their mother Patty calls their persistence what makes them remarkable, and their doctor, Joy Westerdahl, admits on camera that medicine still cannot fully explain how two separate brains and nervous systems coordinate so precisely. The twins and their family have generally declined non-essential testing, keeping the medical questions secondary to daily life. As adulthood approaches and the sheltered life of their hometown starts to end, the film catches them preparing to meet a wider world that has mostly only heard about them as a case study.