The Deep End of the Ocean by Jacquelyn Mitchard

Hardcover-Book 1 of the Cappadora Family series

When Beth Cappadora, a suburban mother and photographer, loses sight of her three-year-old son, Ben, at her fifteenth high-school reunion, not only does her life implode, her family’s does as well. Her husband, Pat, discovers cracks in the marriage where there were no apparent rifts before. More disturbingly, her older son, Vincent, who was supposed to hold on to his little brother’s hand, begins a lifelong descent, intent on proving he is as shameful and unlovable as he believes his parents consider him to be. Then, in what appears to be a miracle, the Cappadora family finds Ben, who has been raised and loved by a former classmate of Beth’s — a woman whose success as an actress has been a mask for madness and depression — and her husband, who adores Ben as his son. Ben has no memory of his family; he is heartbroken and lost.