In the early 1990s the U.S. government created the Valhalla Project, developing an experimental drug that would, in theory, increase soldiers’ stamina and morale. That experimental drug was Valkyr. Unfortunately, all it really did was turn people into crazed psychopaths obsessed with storing an absurd amount of painkillers all over the place and killing a lot of people. The project was eventually deemed a failure and halted. Until Horne discovered it, began producing the drug under the guise of her mega corporation, and started selling it to junkies.
So why, exactly, was Max’s family targeted in the first place? Well, Max’s wife worked in the District Attorney’s office and, while she was there, accidentally found out about the Valhalla project. Horne, in fear of being found out, sent her Valkyr-induced lapdogs to Max’s home, and the rest is history. Once figuring all this out, Max gets pissed, guns down everyone in the Aesir headquarters, and reaches the rooftop, where Horne hops in a helicopter. So what does Max do? He shoots the guy wires of the building’s antenna, causing it to topple down on top of the helicopter. Horne dies. Revenge is sweet.