Following graduation from SUNY-Downstate Medical School in Brooklyn, New York, Michael Mosesson had intended to pursue a Surgical career under the aegis of his former Professor, Clarence Dennis. But life took a different turn. He wound up instead in The United States Public Health Service, stationed at the Division of Biologics Standards on The National Institutes of Health (NIH) campus. During his experiences with research and governmental regulatory control, he began to investigate the circulating precursor of a Fibrin Clot, Fibrinogen. Fibrinogen plays a critical role in many physiological and disease conditions, such as blood clotting, wound healing, hemophilic conditions, thrombotic conditions such as deep vein thrombosis, pulmonary embolism, stroke, heart attacks, and microvascular thromboses (all of which have occurred in COVID-19 patients). Mosesson's surgical plans never materialized, and he turned instead to Fibrinogen, a subject that would involve him as a Scientist and Clinician for the next fifty-two years. In this book, he writes about his investigative, organizational, and societal experiences: - Production of Transgenic Human Fibrinogen in cows' milk. - Discovery of the plasma form of a ubiquitous tissue protein known as Fibronectin. - Identification and isolation of circulating partially degraded forms of Fibrinogen, Fibrinogen Catabolites. - Investigations of Structural and Functional Properties of an Assembled Fibrin Clot, as well as the long-lasting controversy they engendered. - A 50 year-long search to identify a potent inhibitor of clot lysis (Fibrinolysis) found in fibrinogen preparations that is now known as α2-Antiplasmin. - Studies of Dysfibrinogenemias, congenital fibrinogen abnormalities. - Developing a Transgenic Humanized Mouse Fibrinogen model to study the function of the blood clotting inhibitor known as Antithrombin I. - Founding the International Fibrinogen Research Society. Mosesson includes a chapter describing events that accompanied his career as a Pilot, covering a period extending from his days at NIH until his retirement fifty years later. There is also a section written by his friend and colleague, John S. Finlayson, who described the transition of The Division of Biologics Standards to a subsidiary of The Food and Drug Administration (FDA). Finally, he provides an Annotated Bibliography with commentaries and personal insights into many of his published works. The presentations of scientific subject matter are accurate although technical details are minimized for clarity. Narratives are developed around personal interactions and involvements with colleagues, associates, friends, and adversaries, highlighted by many humorous events and anecdotes.