As a child, Peter Parker discovers his father Richard's study has been ransacked. His father gathers concealed documents before Peter's parents take him to stay with his Aunt May and Uncle Ben. His parents leave, but are later killed in a plane crash.
As a teenager, Peter is a student at Midtown High School, where he is bullied by Flash Thompson, and is romantically interested in the beautiful Gwen Stacy. At home, Peter discovers his father's documents, and learns he had been working with scientist Dr. Curt Connors at Oscorp to combine human and animal DNA to cure illnesses. Peter sneaks into Oscorp to meet Connors, who is pressured by his superior Dr. Ratha to complete his serum, and cure the terminally ill head of Oscorp Norman Osborn.
Connors wants the cure himself to restore his missing arm. Meanwhile, Peter breaks into a lab where a "biocable"-a high strength strand of webbing-is created by genetically modified spiders, one of which bites him. During a subway ride home, a fight reveals that he has developed superhuman speed, strength, the ability to stick to surfaces, and a heightened sense of danger.