Scott does well enough on the N.A.S.T.Y. to get promoted to the fifth grade. Mrs. Helperman thinks Spot has run away when he sneaks away as Scott to buy ice cream with Leonard.
Leonard mentions to the cool kids that Leslie uses pink lemonade lip gloss with a hint o' mint, which he had learned from Spot, but that turns into a rumor that he had kissed Leslie on the lips.
Scott and Leonard go to their first sleep-over. Leonard doesn't want to wear a costume because some bully picked on him a year ago that Halloween. After hearing that story, Mr. Jolly starts to cry so much that he ends up dehydrating himself!
When the class goes on a field trip to the circus, Spot falls in love with a circus poodle named Fifi and they instantly fall in love on their date. Spot loves her so much that he decides to leave Leonard to go be with her. Or does he?
Scott thinks he's been branded a bad'un, so he ends up showing the people all at school how bad he can be. When Scott makes slanderous insults against a mailman during career day at school, he ends up getting in trouble for it.
The city wants to turn the dog park into a skateboard park and Scott supports this until his dog friends inform him of their perspective of the park, leaving Spot conflicted on which side he should be on.
Mrs. Helperman decides to write a play incorporating all of her students' holiday and religious traditions, while Spot tries to find out if dogs themselves have any holiday traditions.
Principal Strickler has to go to a principals convention and as his mother can't take care of Tallulah overnight, he asks Mary Lou to take care of her for him to which she agrees to.