Who is Harper Cole from Mortal Fear and what is their importance?

Harper is the husband of Drewe and father of an illegitimate daughter, Holly. He's a gifted musician and soon after college goes on the road with his talent. After only a short time, he decides to give it up, believing that he doesn't have what it takes to succeed. Instead, he begins trading on the stock market and finally makes enough money that he buys and sells only his own stocks. He says that he often deals in commodities that aren't real to him and so once takes possession of what he's just purchased - gold. He retains that gold in a tunnel beneath his farmhouse in Rain, Mississippi.