Explanation:
A major feature of dialogue is that it moves the story forward in a more straight-forward way than a narrator’s explanation would. In the example, Ford and Arthur have barely escaped the demolition of the Earth, and the conversation they hold puts us into the scene and pushes the plot to the next episode. Moreover, the attitude of Ford, who doesn’t look directly at Arthur but suddenly changes the tone of his voice and stands up with a start, makes us have a feeling that something else is going on or is about to happen.
Characters can also evolve through dialogue. In fact, in every good dialogue, at least one of the characters should undergo a change of mood. In the example, Arthur is at first intrigued, questioning Ford about his past. He then suddenly remembers what happened a few minutes ago and returns to a state of shock, moving toward panic. The remembrance makes him angry, and he finally admits that he’s panicking. By the end of the conversation, Arthur is somehow resigned. As you can see, the character goes through a lot of different moods which would lose their effect if they were described by a narrator.
Dialogue increases the story’s pace and makes it more dynamic. It will always be harder to read a whole paragraph where the narrator explains step by step the same things a dialogue can transmit in a few lines. It is clear that the sample dialogue would be very different if a narrator had to explain how Ford recalls the guy with whom he came to the Earth fifteen years ago and how a scared Arthur realizes his planet has just disappeared.
