The price Sean paid for his opinion and action was isolation and loneliness. He felt strongly about the land and the sea, dealt with it reverently and felt it needed protection. (I wondered if was Harper sharing her feelings with her reader. Possibly.) Her character, Sean, became somewhat separated from his peers and even his family because of his rigid beliefs. Ultimately, in two separate instances ten years or so apart, he paid the ultimate price with his own life. Lonely, he took Gabby, younger, more vulnerable than Olivia, to the caves, and he left without her to save his own reputation. This then led to the second situation when he needed to prevent Bronte from exposing his years-ago action. Fearful of being judged by those he valued most, "Everyone will know, won't they?", and unable to live with what he had done, "I know.", he chose to follow "the rush of the water from daylight in the darkness."