In the final installment of this three-part series, Bonnie Petrie and reporter Robin Berghaus go from an isolated stretch of desert along the Rio Grande, where wild peyote grows, to the exuberant rooms at SXSW, where they consider the future of psychedelics-as-medicine, and back to the hallowed halls of the Texas Legislature, where the future of the so-called Ibogaine Bill is uncertain.