A modern top-tier tech genius accidentally is reborn into the Great Tang, becoming an idle prince. Facing court doubts and probes from all sides, he acts like he avoids trouble and would rather lie down than sit, but actually, relying on past-life memories and advanced tech knowledge, quietly builds a prosperous tech city. From improving farm tools to mechanical manufacturing, from commercial layout to urban innovation, he always uses unexpected ways to resolve difficulties. Until the tech city shocks the world, people finally realize this prince is full of hidden depths!