On a remote Irish island, archaeologist Fiona unearths a burial casket containing a mummified figure, unknowingly unleashing an ancient evil upon her team, and her rebellious daughter, Lily. After being propositioned by Fiona’s boss, Lily is inexplicably drawn to the casket, opening the seal. A vicious storm isolates the island as Lily, now possessed by the Morrigan – a vengeful Pagan War Goddess imprisoned centuries ago – begins a bloody rampage. Facing betrayal and escalating horror, Fiona must find a way to save her daughter and stop the Morrigan’s reign of terror, before it leaves the Island.