On the surface, this means that Antonia will be the best source of information if Decoud is still alive, and we have seen that that's the first question Nostromo asks of Captain Mitchell on his return to town. But there is also a strange disorder in these paragraphs, in which Nostromo (whose mind is "troubled") seems to be wondering if the dead Decoud will come back for more silver, then realizing that the ghost would fly to Antonia.