You shouldn't send offensive letters to your teachers.
Dennis is with his mom, and he has just received his report card from his teacher and is looking at all D's.
Dennis wants to react angrily to the report card.
Dennis takes the report card and crumples it before throwing it against the wall.
Dennis sends a letter to his teacher calling her names and outlining how he might follow her around at night.
Dennis mom chuckles as she watches Dennis' tantrum knowing that he'll be over it soon.
Dennis' mom is terrified and saddened that her son would be this upset.