Over the past 30 years ecstasy has become one of the world's most notorious drugs. No other illegal substance has had the same effect on fashion, music and how we party. This film follows two recreational ecstasy users over one night and, using computer graphics, journeys inside the body and the brain to explore how the drug creates its highs and its lows. With access to cutting edge research at the University of Chicago we find out how ecstasy creates empathy in the user and how this could one day lead to the drug being used as a life saving prescription medicine for use in therapy. Whilst ecstasy is the perfect high for some, there are those for whom ecstasy is agony - this film tells their story too: a young woman whose use of the drug ended her up in the psychiatric ward, a 17-year-old whose ecstasy use landed her in a hospital, and a mother whose son died from overheating after taking ecstasy. Killer chemical or the ultimate feel good high, this is the inside story of how ecstasy works.