Faith Moore is a devoted yet frustrated wife as her workaholic husband's increasingly distant attitude puts a strain on their once perfect marriage. When yet another unexpected business trip dashes Faith's plans for a romantic lunch with her husband, she becomes convinced he is having an affair with his vibrant young work colleague, Kit. So when Walter York walks into her life she is flattered by his attention and in a moment of weakness seeks solace in his bed. Desperately regretting their passionate one night stand Faith tells Walter that she can never see him again. However Walter believes he has found his true love and obsessively stalks his new "Fiance" determined to prove his devotion. As Walter insidiously invades Faith's world she realises that he will stop at nothing in order to fulfil his fantasy.