From the moment Matthew (Josh Hartnett) sees Lisa (Diane Kruger), nothing else matters. She walks past the window of the shop where he works in the Wicker Park section of Chicago, and he's immediately captivated. He follows her, they meet, and soon they fall deeply in love. Everything about their relationship seems perfect -- until the day she disappears without a trace.
Two years later, Matt has built a new life for himself, but he's still haunted by her memory and the nagging torment of unanswered questions. Then he catches a quick glimpse of someone he thinks must be her in a bar...but is it? Thus begins a twisting, obsessive search for the woman who captured his heart years ago -- and for someone who's playing with his mind right now. Intricately moving back and forth in time and revealing the story from varying perspectives, Matthew's search for the truth will lead him deeper into the mystery, with each discovery more deceiving than the next.
Obsession can go both ways, and Matthew discovers it's possible to love someone too much...