A year after gaining spider-like abilities, Miles Morales has been training under Peter Parker and is settling into his new home in Harlem with his mother Rio. When Peter leaves New York to assist Mary Jane Watson overseas, Miles becomes the city's sole Spider-Man. Almost immediately, a violent conflict erupts between the Roxxon Energy Corporation, which is pushing a new experimental energy source called Nuform, and a high-tech criminal army known as the Underground. The Underground is led by a masked figure called the Tinkerer, whose identity hits close to home for Miles. As the fighting threatens to consume Harlem, Miles must navigate the responsibilities of protecting his community, supporting his mother's city council campaign, and uncovering the truth behind Roxxon's new technology and the real motives driving the Underground's war.