Mr. Wilson accidentlly gets a space helmet that belongs to Dennis stuck on his head.

Dennis and Mr. Wilson camp out on a moutain so that Dennis can join the Junior Pathfinders club.

Henry gets a ticket for walking on the grass in the park. When Mr. Wilson hears about it he thinks it isn't fair, So he convinces Henry to go to court and contest it.

Dennis is using numbers for a football play which is the combination to Mr. Wilson's safe, So Mr. Wilson and Henry get Dennis so confused that he forgets the combination. Then Mr. Wilson forgets it. Now they are in a real mess because Mr. Wilson has something very important locked in the safe. So Mr. Wilson tries everything including trying to hypnotize Dennis so he can remember the combination. He ends up hypnotizing himself and remembers the combination at last.

Mr. Wilson and Henry both invest in a house that is known to be a haunted house.

Dennis' school is putting on a play which Mr. Wilson ends up being in (not by choice) because him and Tommy (who is also in the play) get handcuffed together before the play starts.

Mr. Finch is having a contest that when the fifty-thousandth customer walks in his store they will win 5 minutes of free shopping of which Mr. Wilson is determined to be the one who wins.

Mr. Wilson coaches Dennis' Pee Wee League baseball team because Dennis' dad (who originally was the coach) got sick.

Mr. Wilson wants to represent Scotland for Dennis' School

The school test scores mistake Dennis as a genius.

Mr. Wilson tricks Dennis into taking a silver coin that says GOOD LUCK and a horseshoe on it instead of 50 cents that he owes him for cutting his lawn. Mrs. Wilson is very angry with him about it. So, she and Alice start a scheme of their own by making lucky things happen to Dennis all day. Mr. Wilson soon starts to believe that the coin was lucky after all and is sorry he ever let it go. He then realizes that it was all a charade to teach him a lesson.

Dennis, Henry and Mr. Wilson go out in the woods and cut down a big Christmas tree which ends up getting almost destroyed by the time they get it home.

Dennis opens a bank account at the bank of where Mr. Wilson works at and causes a lot of chaos at the bank.

Dennis' cub scouts are putting on a circus of which Mr. Wilson is the Lion in the circus, which is suppose to be a secret from everyone.

Mr. Wilson holds a bird lovers session at his home Where a woman does bird calls that sounds just like a bird.

Mr. Wilson agrees to give Dennis his magnifying glass if he doesn't talk around him for the day.

Dennis is put on the spot when he askes both Mr. Wilson and Mr. Mactavish to represent Scotland in his school project.

Dennis enters his frog in the frog jumping contest with Mr. Wilson as his partner who has a bet with Sgt. Mooney that Dennis' frog will beat his.

Mr. Wilson gives Dennis a Gold watch in his will. Soon after that Mr. Wilson begins to feel old and is convinced that he has short time to live.

Mr. Wilson's Uncle comes to visit him and convinces him that he isn't in shape, so he starts a physical fitness program and forces Mr. Mitchell and Mr. Wilson to be in it.

Mr. Wilson plans to have a quiet evening at home, but his plans change when Henry needs a sitter for Dennis.

Mr. Wilson gets his wallet taken by a pick pocket, So Dennis and Tommy try to find the crook for the police.

Mr. Wilson hires a housekeeper for Mrs. Wilson but soon regrets it when the housekeeper tries to tell Mr. Wilson what he can and can't do in his home. Mr. Wilson then tries to get rid of her.

A big shaggy dog followes Mr. Wilson home and Mr. Wilson tries to get rid of it.

Dennis does a documentary film of the town for a school project with Mr. Wilson's help.