When Kit's best friend gets dumped by his boyfriend, he begs her to ditch her family responsibilities for a quick, idyllic weekend in the Montana mountains. They'll soak in hot springs, then sneak a vape into the local dive bar like old times. But it's soon clear that this getaway only gets Kit closer to something dire and unfathomable that's been building inside her for years, ever since her sister Julie died. Back in the Dallas suburbs, Kit tries to settle into her usual routine: long afternoons spent taking care of her irrepressible young daughter, going on therapist-advised dates with her concerned husband, and reluctantly taking her mother's phone calls. In the secret recesses of Kit's mind, though, she's dreaming of an impossible threesome with her kid's pretty gymnastics teacher and the cool mom she just met at the playground.