Satan can grant you any wish, the only condition is thirty years of life. Human greed is endless. After exchanging lifespan for power and glory, he began to pursue the method of eternal life, but little did he know that he was playing into the hands of Satan. Mary, a 30-year-old working-class young woman, exchanged her thirty-year lifespan for a chance to start over, but accidentally entered the magical age of declining science. How should an older young woman deal with herself in a different world?