While Pumpkin is at Fluttershy's, Pound is trying to get his parents and Pinkie Pie to stop trying to potty train him by holding it in whenever he's put on the potty. Mr. Cake and Pinkie Pie try in vain to get him to use it, then take him down to Mrs. Cake, who uses reverse psychology on him, and it works.
Pound then feels vengeful towards Pumpkin for sticking him to his potty and flushing his pacifier, and gets an idea for revenge during lunch from a cartoon about machines written in the newspaper by someone named Pony Goldberg: make a machine to put Pumpkin's potty on her face.
Pound builds his machine with Pinkie Pie's help (not telling her what it's for) and then Discord arrives. Some time later, Pumpkin arrives home and Pound leads her into the bathroom, where she trips on a rope that's attached to a plank with a marble attached. The marble rolls down towards a gear that triggers a raceway, that leads to a plastic arrow, that strikes a whoopee cushion that deflates and sets off a toy train, that slices another rope, which is attached to Pumpkin's potty, which falls on her head.
This chapter provides examples of
- A Dog Named "Dog": Apparently, the cartoonist is Pony Goldberg.
- Blowing a Raspberry: Pound blows raspberries at Pinkie Pie to express defiance.
- Full-Name Ultimatum: Pinkie addresses Pound as "Pound Cake" when telling him to use his potty.
- Reverse Psychology: Mrs. Cake tells Pound that he doesn't have to use his potty, but then adds that she did a lot for him.
