While the Civil War rages on between the Union and the Confederacy, three men – a quiet loner, a ruthless hitman, and a Mexican bandit – comb the American Southwest in search of a strongbox containing $200,000 in stolen gold.

After reuniting with Gwen Stacy, Brooklyn's full-time, friendly neighborhood Spider-Man is catapulted across the Multiverse, where he encounters a team of Spider-People charged with protecting its very existence. However, when the heroes clash on how to handle a new threat, Miles finds himself pitted against the other Spiders. He must soon redefine what it means to be a hero so he can save the people he loves most.