Pufferty is too big to have fun at the FunFair, so the twins decide he can be the Roller Coaster; when McCoggins attaches a booster pack, the pup speeds out of control.

The twins fix up Madame Au Lait's old stunt plane, which they hope gets her to perform her high-flying tricks.

At the Funfair, everyone's having a blast, except Pufferty, who's too big for the rides. Tommy and Tallulah turn him into a roller coaster with McCoggins' help. Things get wild as Hopparoo maxes out the booster, but teamwork saves the day. They rev up for Chime Time and Tooteroo's strength test goes awry.

The twins find the bones of an ancient Clockosaurus, put them all together, and set it loose on the town.

Friends race against time to keep clock ticking.

The twins cause McCoggins' robot to short circuit and go berserk and they need it to fix a section of track before Chime Time.