Chapter four, “Travelogue: Journeying Underground,” takes the reader through Pollan’s personal experiences with three different psychedelic compounds. Once psychedelics were categorized as class one substances, the use of psychedelics went underground. Many people were, and still are, interested in using psychedelics and seek to undertake psychedelic experiences under the watchful eye of an underground guide. Despite not being formally regulated, many underground guides adhere to strict standards when assisting individuals under the influence of psychedelics.