The Deep End of the Ocean (1999)

Beth Cappadora is like most mothers--loving, devoted and occasionally overwhelmed by the demands of caring for her family and maintaining a successful career as a photographer. With her small three children in tow, she arrives at a hotel for her 15th high school reunion weekend. In the middle of the crowded lobby, she looks away for a moment--and in that moment her three-year-old son Ben disappears. A frantic search turns up nothing; he has vanished in the blink of an eye, seemingly without a trace. As hours turn into days, days into months, Ben's disappearance has a devastating effect on Beth's ability to cope, creating tensions between her and her husband Pat as well as her son, Vincent. Time goes by, and with Pat's help, Beth and the children go back to leading a seemingly normal life. Then one day, some nine years later, a boy knocks on the Cappadora's door, a boy who is the same age that there missing son would be now--could it be him?