People
"Yes, it is," said the Professor. "Wait --" he motioned to Richard, who was about to go out again and investigate -- "let it be. It won't be long."
— Douglas Adams
Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The Professor stops Richard from going to investigate and asks him to wait, saying it will not be long. The passage sets an impulse to act against a request for patience. What is happening remains unspecified here, so the emphasis falls on that small interruption and reassurance.
Context reviewed