(Strip Number 1381, Original Publication Date, 8 December 1987)
Panel 1: We find John at the clinic patting himself down trying to find something as he tries to talk himself out of talking to the bank about buying the evil yellow car.
Panel 2: As he roots through his pockets, he tells himself that if he trades in his sedan, he won't need a great big loan.
Panel 3: His plotting to ruin Elly's life buying the sports car and thus disgrace her in front of her mother and the neighbours is interrupted when Jean asks him what he's thinking because he seems preoccupied. He mutters "Oh?" so as to ask why she said that.
Panel 4: Why she said that is that he left his pen in the autoclave.
Summary: This, I should think, is meant to castigate Rod for pointlessly complicating his life opening up that dental practice when the simple thing would be to keep on serving Lynn without question.