This episode looks at words that contradict themselves, carrying opposite meanings at once or shifting dramatically over time. Manufacturing suggests mass production today, yet it comes from Latin meaning 'made by hand'. A model can be an unfinished prototype or a finished ideal, while mistress carries both admiration and scandal. Execute traces back to a Latin root meaning, 'to follow', but does it mean to begin or to kill? Is supporting someone holding them up or holding them down? And why do alarms go off when on seems more logical?