The Unheard follows 20-year-old Chloe Grayden (Lachlan Watson), who after undergoing an experimental procedure to restore her damaged hearing, begins to suffer from auditory hallucinations seemingly related to the mysterious disappearance of her mother.
It follows a college student as she boards a party train for Halloween, and ends up fighting for her life when a mysterious assailant begins killing the people one-by-one.
Confined to their glasshouse, a family survives The Shred, a toxin that erases memory. Until the sisters are seduced by a Stranger who shatters their peace and stirs a past best left buried.