Caius ceased to hope that he would meet her by chance, because he knew he would already have done so if it were not willed otherwise.

Then his mind grew restless again, and impatient; he could not even imagine where she could lie hidden, or what possible reason there could be for a life of uncomfortable concealment.
Caius had not allowed either O'Shea or Madame Le Maitre to suspect that in his stumble he had involuntarily seen his companion on the midnight journey.

He did not think that the sea-maid herself knew that he had seen her there.

He might have been tempted now to believe that the vision was some bright illusion, if its reality had not been proved by the fact that Madame Le Maitre knew that he had a companion, and that O'Shea had staked much that he should not take that long moonlight walk by her side.
Since the day on which he had become sure that the sea-maid had such close and real connection with human beings that he met every day, he had ceased to have those strange and uncomfortable ideas about her, which, in half his moods, relegated her into the region of freaks practised upon mortals by the denizens of the unseen, or, still farther, into the region of dreams that have no reality.

However, now that she had retired again into hiding, this assurance of his was small comfort.
He would have resolutely inquired of Madame Le Maitre who it was who had been sent to warn him of danger if need be upon the beach, but that the lady was not one to allow herself willingly to be questioned, and in exciting her displeasure he might lose the only chance of gaining what he sought.