Based on the story of the same name from Small Railway Engines.

Duck's driver boils an egg in his whistle, which is now clogged and makes a funny noise. The engines tease Duck about his whistle, especially Mike who says engines without whistles are improper engines. Later, he pulls passengers on the line and encounters a cow. He blows his whistle so hard that it flies far away into a field. Mike insists they look for his lost whistle, but the passengers decide to whistle for him instead.

Henry is accidentally given some "glow-in-the-dark" paint atthe Steamworksand is confused as to why everyone he comes across runs away from him. It is shown that his paint is glowing and laughs at the misunderstanding. When the others tease him for being a scaredy engine, Henry devises a plan to get them back.