Merle’s life begins to splinter when Sinaloa (Sophie Reid), the half-sister she never knew existed, appears on her doorstep in Texas. Initially distrustful of this enigmatic woman, a bond quickly forms between the two sisters. As Merle (Allison Tolman) allows Sinaloa into her life, Sinaloa reveals a quiet fury to Merle through her music. Sinaloa’s fierce attachment places Merle’s career aspirations, her relationship to her mother, and even her impending marriage in jeopardy. Merle fights to keep her world together while Sinaloa’s increasingly intense and erratic behavior threatens to erupt into something much darker.