Freya places a protection spell on the compound when it's discovered that the Hollow's latest servant is on the loose, but it forces Klaus, Hayley and Hope to remain inside. Meanwhile, Elijah takes matters into his own hands when Vincent is reluctant to perform a dangerous ritual needed to strengthen their defense against the Hollow; and Freya enacts a risky plan that brings her face to face with their latest threat, but an unexpected twist leaves her life hanging in the balance.

When The Hollow sends a terrifying message to Vincent, he must team with Haley and Freya to embark on a desperate mission to stop the Hollow once and for all - even if it requires a heartbreaking sacrifice. Refusing to allow anyone in his family to pay the high price of defeating their enemy, Klaus makes a surprising alliance and enacts a plan that threatens to change the Mikaelson family forever.