The man and the boy are running from the fire that is destroying the world. They are trying to survive by finding anything they can. They scavenged numerous stores, houses, and even boats.
Man vs. Self
A group of men showed up when the man and boy were sleeping so they went to hide. While they were hiding one of the men showed up and took the boy hostage. Then the man killed the guy holding his son hostage.
Man vs. Man
While the man and the boy were walking through the woods they noticed a campfire and went towards it. When they got to the campsite the people that were there had left. The man and boy noticed that there was something cooking on the fire and it was a dead baby.
Man vs. Self
While the man and boy are resting for the night at their camp the boy asks his father a very important question. He asks him what he would do if he dies and the father replies by saying that he wants to die too. The only reason that the father is continuing to survive is because of his son.
While the man and the boy were on the beach their supplies were stolen. The man went to a boat in the water and left the boy. While the man was gone the boy fell asleep and someone came and stole everything.
While the man and boy are on the beach and the man gets really sick and ends up dying. Before he dies he tells his son to carry the fire which is the hope of humanity returning to normal. His son is now devasted and doesn't know what to do until a family comes and saves him.