Frank Parker: early mechanized cavalry theorist -- A reason to be! -- The struggle for an innovative doctrine and a combat car -- Cavalrymen looking for new mounts and a tactical doctrine -- The "great cavalry debate" over new opportunities -- So he lost it all? -- Sneak and peek, or fight? -- Mechanized cavalry from Normandy to the end of the war -- The terrible turmoil of postwar Germany and the U.S. Constabulary -- Conclusion.