The Hollow anchors itself to the living world by exploiting the darkest fears and past traumas of powerful supernatural beings.
: The final scene reveals that Sofya is actively conspiring against the Mikaelsons, working with a witch named Dominic. [S4E5] I Hear You Knocking
: Though the intended sacrifice failed, the Hollow accepts Marcel’s blood and grants his allies a magical thorn capable of killing an Original. The Hollow anchors itself to the living world
: Freya risks her life to create a cure for the infection the Hollow placed on Klaus, solidifying her bond with Keelin as they work together to protect the family. Key Revelations [S4E5] I Hear You Knocking