The story takes place in a small town called Chester Mill. An indestructible "dome" that fell from the sky cut off all contact between the town and the outside world, and also ended the town's illusion of peace for many years. Soon, the residents of the town saw the reality that they had become "trapped in a jar", and with the continuous consumption of resources, chaos inevitably occurred. After the accidental death of the old sheriff, the burden of maintaining law and order in the town fell on the shoulders of the young deputy sheriff Linda (Natalie Martinez), and Congressman Big Jim (Dean Norris) saw a great opportunity to become a "ruler". Some strange symptoms appeared in the four children of the mill town. In the woods, they found a small dome and became its protector, because the dome seemed to convey some messages to them. When the breath of crime and danger gradually spread in the town, more and more signs showed that it was not a coincidence that the dome chose the mill town.