The boy's father gives him a bag of nails and tells him to hammer one into the fence each time he loses his temper. The first day, the boy hammers 37 nails. Over time, with his father's encouragement, the boy learns to control his anger and hammers fewer nails each day. Eventually, he is able to remove all the nails from the fence. His father tells him that while the nails are gone, the holes they left remain, just as hurtful words can leave lasting wounds, even if apologies are made. The story encourages controlling one's temper and being mindful of how words can hurt others.