Hank explains that DNA stores our genetic instructions and illustrates how DNA is structured. He explains the parts of the Double Helix structure and uses a book to put into perspective just how many base pairs are tightly packed in each chromosome.
Peter gets home after being bitten by a genetically-engineered spider during a school field trip. He falls ill from the spider's venom, and while he's asleep the venom alters his genetic makeup. He wakes up to find his body has changed dramatically overnight.