The extreme days are scorching, the extreme nights are freezing, and the world is torn into rings of scorching embers, rings of twilight, and circles of shadow. Fang Muxi carries the "Ark System" to carry out a doomsday mission in exchange for a glimmer of survival and reconstruction; Han Yao bears the betrayal of his younger brother and walks hard between hatred and justice. They redeem each other between the black salt storm and the group mutation, changing the "bridge" from a tool of power to a road to everyone. When sacrifice becomes the price of reconstruction, how should they choose...