Norman Spencer (Ford, slothful) and his wife Claire (Pfeiffer) are so happily in love in their lakeside mansion that you know something dreadful's going to occur. It's just a case of when. But Zemeckis keeps the ambiguities coming. While Norman is content to pursue his career as a research scientist, Claire still suffers the psychological after effects of a car accident and prefers to stay at home with her thoughts. Then the strangeness begins: she starts hearing noises. Echoing Rear Window, she even begins to suspect her new neighbour has killed his wife. Worse, turning off the bath, she briefly catches the horrifying reflection of a young woman. Either she's off her rocker or the woman's trying to tell her something. But what, and why? Who is she anyway? Claire stumbles into her own investigation and proceeds to put her foot right in it. At which point - after a slow build that at times makes every hair stand on end - Zemeckis rolls out every thriller cliché there is. A pity, because until then it's a smart, realistically staged, adult-oriented and extraordinarily effective domestic chiller.