The basis: Alex and Lisa are neighbors and eventually roommates for awhile. They become pretty good friends. One day Alex sees Matt and falls in love with him. She takes a video camera with Lisa on it to get repaired. We find out that Lisa was the mysterious girl Matt wanted to hook up with. They hook up and fall in love. One day Lisa just disappears. 2 years pass and Matt has somewhat moved on. He has a new girlfriend, Rebecca. At a restaurant he thinks he sees and hears Lisa. This sends him on a trail to find her. (He skips his business trip to china) All his detective work leads him to the apartment of Alex. But she claims she's Lisa. She just happens to have the same name and shoes. Matt begins to think something is fishy. He starts not believing her and continues his search. She tries to stop him. Taking some minor stuff out, what ends up happening is Luke, Matt's good friend, going out with a girl who Matt never sees. Turns out, it's Alex. She is just using Luke to get close to Matt, who eventually finds out Alex?s plan after he buys her a pair of shoes (that Lisa bought and broke) and they're two big for her. He knows something is up because Lisa?s same size broken shoes are at that apartment. Luke brings Matt to breakfast or lunch and Alex is there. She tells him what she did, she never told Matt that Lisa went to Europe for dance and that she loved him. It was in a letter she had written. She deleted all his messages. (She was given a key from Lisa to drop the note off) she told Lisa on the phone she saw Matt with another girl. Luke tells Matt Lisa called (Matt left a note for Lisa where he thought he saw her just in case she came looking for her compact she left) and says "tell him to meet me at 3 o?clock tomorrow. He?ll know where." (Wicker Park) Alex mentions Lisa is leaving for London as well. He goes to Wicker Park it's to late. He goes to the airport. Sees Rebecca (his current girlfriend there to pick him up from the business trip he was supposed to be on) and tells her he loves someone else. She gets mad and leaves him. Lisa is crouched on the floor talking to Alex on the phone as she begins to tell Lisa what she did. Lisa hangs up and is crying. We see Matt see her. (cue coldpay's - the scientist, a great song for this scene "Come up to meet you, Tell you I?m sorry, You don?t know how lovely you are I had to find you, Tell you I need you, Tell you I set you apart,") he gets closer and crouches behind her and starts crying. She turns around, they kiss and hug, movie ends. Great flick.