The engineer listens to music on one side of a hill, writing down and keeping track of any sections of music that are too fast. The radio machine then sends the signal via lightning bolt to a tower, which then broadcasts the message: "Why is there a light on top of the tower?" (again, via lightning bolt) to anyone on the other side of the hill.
Notice that our knitting lady from Page 2 is now alone. She is the only member of the family who cares enough about the question being broadcast to await an answer. Radio demands loyalty, and Knitting Lady will be well-rewarded in time.
Next: The Expendables