When the vampire aristocrat Leonardo was executing traitors in the dungeon, he rescued the human girl Irene who was bitten by a hound and transformed her into a vampire. Irene's blood has a unique sea flavor, similar to Leon's wife Lydia who died three hundred years ago. Leon bound his life to Irene through a blood contract, but gradually discovered that she was involved in a conspiracy: Irene is actually the container for Lydia's soul fragments, and the Elders are trying to use her to open the door to hell.
Erin has both the blood of the Holy Grail and the blood of Cain flowing in her body, possessing the dual power of healing and destruction. In the process of fighting against the leader of the Presbyterian Church, Albert, and the original vampire Cain, Leon and Irene revealed the truth. In the end, Irene sacrifices herself to close the gates of hell, and Leon activates her power at the cost of his life. The blood of the two blended to form a new bond, the gate to hell was sealed, and their story ushered in a new life.
Purpose: Too much memory should not be left to the dead