We have only one family and a rule that says that under no circumstances should a sound be made. After all, there is an inexplicable evil in the world, there are creatures on the surface, which will immediately resort to the slightest noise and eat you.
Here is the father of the family, who is trying hard to protect everyone from the clutches of creatures, this is his meaning of life, a way not to go crazy. His wife's pregnant, the baby comes right here. How do you give birth in a world where there should be absolute silence? And children who haven't yet lived well, who have to accept the rules of this world and try not to lose their childhood.
If the second part of the film is like the second one, I will definitely watch it.