Arthur A. Patchett, the 1993 recipient of the E. B. Hershberg Award for Important Discoveries in Medicinally Active Substances, recounts his career in drug discovery—titled 'Excursions in Drug Discovery'—highlighting contributions to the design of antihypertensive drugs enalapril and lisinopril and the discovery of cholesterol-lowering drug lovastatin. He reflects on broader aspects of his work, which spanned natural products, lead modifications, and de novo design across medicinal chemistry areas. Early work included steroid structure-activity relationships (e.g., topical anti-inflammatory steroids) and analgesic drug development (e.g., conformationally restricted propoxyphene analogs). The Fermentation Products for Screening Project (FERPS) led to lovastatin's discovery from an Aspergillus terreus extract, identified via HMG-CoA reductase inhibition. For angiotensin converting enzyme (ACE) inhibitors, he details the transition from biproduct designs to optimizing analogs (e.g., enalapril, a prodrug with oral activity; lisinopril, a lysine analog with unexpected oral absorption). Later work focused on bacterial enzyme inhibitors (alanine racemase, alanine ligase) and recent research on macrocyclic renin inhibitors and AT1 antagonists. Patchett traces the evolution of drug discovery from random compound synthesis to mechanism-oriented enzyme inhibitor design, stressing the biology-chemistry interface. He concludes with future opportunities: computer-aided screening, molecular modeling, improving pharmacokinetics, and understanding transport/metabolism, while acknowledging his associates and the award sponsor.