Who is Hiram Wallace from Jacob Have I Loved and what is their importance?

Hiram, also known as the Captain, is a mysterious man who visits the island and ignites the imagination of its inhabitants. Later, we learn that he is the only son of a crab fisherman, who once lived on the island but left in disgrace after panicking during a lightning storm. The Captain is Louise's first love, though her crush does not return her interest, thus, breaking her heart. He later marries Auntie Braxton.