We never do learn what Charles Gould's "plan" here is, or for what he was buying time. His goal is the provincial counter-revolution, but to his mind Barrios remains unreachable and the miner army unexpected. The suggestion in this scene is that he is buying time purely for Mrs Gould's sake, without any larger "plan" at all. Later, one assumes that he is informed of Nostromo's ride to Cayta, and is waiting for Barrios' arrival, but that possibility is not present yet.