An interview with Carmen Helisten at Pharm Chem Laboratories, who talks about the impurity of street heroin, which is often cut with procaine. CU procaine in a bottle, syringe withdrawing liquid from glass vial, rows of vials and bottles on white surface. CU bottle labeled "heroin" being picked up by lab technician, tests being performed on blotter paper to determine the contents of a drug. Narrator explains that heroin has been cut with everything from quinine to Ajax.