"Be careful who you love, it just might kill you."

When Sera's father is killed in a horrific accident, all he leaves behind is a mysterious key. Sera places the key on a chain around her neck and vows to avenge her father. Strange characters arrive in town including the otherworldly Night Angels, who claim to be sent for her protection.

Sera falls hard for one of them—exotic, arrogant Peter. But what if his promise of love is only a ruse to gain access to the key? As Sera's connection to the key grows, so do her supernatural powers. Guided by clues left by her father, Sera searches for the hidden chamber beneath the city, hoping to save what lies within before the sinister mayor and his deadly followers drown humanity in a bloodbath.