The ups and downs experienced by the four children are unparalleled. They live under the arrangement of fate. The destined destruction of North Vietnam forces them to embark on the important task of repeating North Vietnam. There are many crises along the way, and they even fall into a crisis of trust... But all of this will not affect their friendship in the slightest. Whether they can rebuild North Vietnam, the mysteries will be revealed one by one. What is the secret behind this?