The Morrigan (2026) Plot Summary & Ending Explained

The ancient seal that Fiona and her team uncover is the prison of the Morrigan, a dark Celtic goddess once mutilated by invading Christians. When Lily, drawn to the casket despite her mother’s warnings, breaks the seal, the spirit rushes into her, turning the teenage girl into a violent vessel. She slaughters the archaeologists and their host, her eyes glowing with a cold green light, while the Morrigan taunts the remaining survivors and even throws Francis off a cliff.

Realising that the only way to stop the deity is to destroy its current host, Fiona forces Lily to inject herself with a massive dose of insulin, hoping the resulting shock will expel the spirit. The plan works long enough for Lily to scramble out of the tunnel, but the collapsing scaffolding that Fiona set up traps her mother inside the rubble. Fiona’s desperate last attempt to seal the cave seals her fate; she is buried beneath the fallen stone as the rescue team arrives.