peggy thomas were over and he'd soon be home, he told her. and for jean, that was a reason to believe. >> i thought there was some hope. i didn't want to let go. >> and for a brief moment in september 2003 jean looked as if her perseverance would pay off. jim invited her out to las vegas for her 40th birthday. for several days he wined and dined her, but her dreams of a happy ending she says, vanished when her husband turned to her in bed one night and told her he intended to make his darkest dreams come true. there was a man who needed to die. coming up -- >> not the kind of thing a wife wants to hear, but jean has an even bigger shock coming. >> it was like getting kicked in the stomach. life was over at that point. >> when "dateline" continues. seresto, seresto, seresto.