In the 22nd century, Deunan Knute and Briareos venture into the remains of New York, seeking the mythical city of Olympus in the post-apocalyptic world of Appleseed Alpha. Along the way, they join forces with Iris and Olson, who, like them, have a mission to fulfill. Together, the four comrades make a pact to embark on their quest as one. However, their journey takes a perilous turn when they encounter Two Horns, the warlord of the ravaged metropolis, who hires them to take down bipedal combat machines. As Iris sets out to prevent the evil cyborg, Talos, from gaining hold of a hidden weapon, she unwittingly triggers a massive war machine at Talos's behest.