Teenager Jimmy Donovan struggles to survive in a household with a drug-addicted mother and a six-year-old sister, Angie, by selling marijuana in a diverse, suburban neighborhood. After his mother is hospitalized, Jimmy makes the difficult decision to begin pushing heroin in order to make the tuition payments for Angie, which will keep her in a safer, private school. This new business venture sparks some problems and sends Jimmy and his friends into a spiral of bad events. His struggle to stay afloat is filled with numerous problems, all of which surround his world in what he calls "kryptonite."