If you know, you know. All the details should be familiar to you because this is a book based on the plot of the original franchise of Spider-Man: Into/Across the Spider-Verse. Anyways...
After a hole was ripped carelessly into the universe (By someone called*intense coughing* Spider-Man), entities started to appear across dimensions, a government funded megacorporation that focuses on science, chemistry, astronomy, technology, you name it, was blamed for the cause. Neglecting the presence of a private multi-dimensional security group that is, oddly enough, filled with a bunch of Spider-people, the US government launched their very own multi-dimensional security group known as Nexus Corps (more detail will be provided later in the book about Nexus Corps). All was going well, at least for a few months, Nexus Corps doing well as they were assigned to. Until, that is, they discovered the Spider-people. Long story short, the security of the multi-verse was jeopardized, endangered, and collapsing.