10 years ago Ellie was adopted by a pair of biotech millionaires. In a designer mansion in Malibu, the girl is celebrating her 16th birthday, but it brings her no joy, as she has a serious autoimmune disease and no friends. Secretly from her parents, Ellie sneaks out to the beach, where she finds a friend named Brook. They spend more and more time together, and soon Brook begins to suspect that Ellie’s parents are hiding something.