WWIII: Nexus

Anna's world shatters when she saw her brother kill their father, who apparently hides secrets from her. World-shattering secrets. It turns out one of those is a killing serum, which gives the injected a sort of blood lust. She needs to keep this from the very people her father was planning to sell it too ...but it was too late. Now she needs to sacrifice something: Her safety, or the world.