HELP FINDING THIS BOOK QUICKLY

[Kati]

This book is about a Hollywood film director who marries a young woman. They have two children. While the husband and son are away, the wife is attached and the girl locked in a closet. Not to add spoilers to the book, ultimately the film director leaves his wife and takes the children and disappears. Fast forward, the kids are grown. They have lived in privacy, never leaving the home, being home schooled, etc. The boy leaves, the girl follows to try to find him, and ultimately all the mysteries are solved. Anyone have a clue to the name of this book and author. Thank you.