A: We'll wait till dark. B: But why? A: Because it's the best time. B: I don't understand you. A: Look here...really....can't you see that it is perfect! B: Well....if it were moved just a little to the left...... A: Don't touch it! B: But, just look through this hole! You can see......
In preparation:
What is happens before the conversation? Where are the speakers? Who are the speakers? What are they planning? What is "it"? What happens after this conversation?