Spencer Slips Up! is a rhyming magazine story.
One day, the Duke and Duchess of Boxford go for a ride aboard their "Silver Bullet" train. Spencer boasts to Harold that they call him the "Silver Bullet" because he goes so fast. Shortly, Spencer reaches a stretch of track covered in fallen autumn leaves. Spencer's wheels cannot grip. Then, Harold arrives and hovers low. His blades blow the leaves away and Spencer starts to pick up speed and he promises he will not show off again.