Harlan Coben is a master of this genre. Although this book is enjoyable, it is not quite as good as some of this other ones. The idea that a couple who love each other more than anything would completely separate from one another for years, yet yearn for each other, makes for a great mystery. However, the reason for such a separation has to be ultimately very compelling, and I don't think the author pulled that difficult task off. It is nonetheless a worthy page-turner.