Mr. and Mrs. White and Herbert are talking to Sergeant Major Morris, learning about his time in india and the monkey's paw. Warning them of its dangers he throws in in the fire, but Mr. White reaches in after it. This is important because it is the lead in to everything else, this how the White's end up with the monkeys paw, and it is the reason for the rest of the story.
Mr. White makes his first wish of 200 pounds. Instead of simply receiving the money, they ended up getting the money from a compensation of their sons death. This is important because it during this part they realize that their wishes are going to come with consequences. They realize that they should now use the paw with more caution.
Mrs. White is opening the door for "Herbert," meanwhile Mr. White is wishing for whoever is at the door to go away because he is afraid. This is important because it finishes off Mr. White's three wishes, they think that they are about to receive their son back, but because of the past, and fear, Mr. White wishes away who ever is at the door, and in the end they end up without their son, but without any more bad consequences.