Stella is single-minded, driven, and intense. Her sister Ellie is a talented runner too, but she also lets herself have fun. Both Stella’s and Ellie’s lives are upended when Mila comes to town. Mila was the top runner on her team back home and Ellie and Stella see her as a threat. But Ellie can’t help but be drawn to her warm, charming personality. To her surpise, Stella too can’t help but see Mila as funny, and strong. With regionals approaching, the pressure is on. But then, suddenly, Mila goes out on a training run and never returns. No one knows what happened, but all eyes are on the Steckler sisters.