Director Robert Zemeckis' 2000 ghost movie What Lies Beneath has several layers to its mystery, but here's why Claire was being haunted. What Lies Beneath has oddly faded a bit from the popular consciousness in recent years, despite being directed by one of the most decorated filmmakers in Hollywood, and starring two hall of fame-caliber A-list actors in its leading roles. While reviews from critics were mixed, What Lies Beneath was a big box office success, nearly tripling its $100 million budget worldwide.

It's possible this fading away is the byproduct of the 2010s introducing so many options of things to watch that something like What Lies Beneath, a good but not excellent ghost story, fell by the wayside. Whatever the cause, Zemeckis' film is now streaming on Netflix, offering its millions of subscribers a way to either get reacquainted with the once very popular film, or discover it for the first time. After all, What Lies Beneath wouldn't be the first time a movie got a second life thanks to streaming.

Related: The Sixth Sense Wasn’t 1999's Best Ghost Movie

For those who have seen What Lies Beneath, there's a chance the twisty plot led to some confusion over what exactly happened to Claire (Michelle Pfeiffer), and why the ghost was haunting her. It's time to clear that up.

What Lies Beneath Ending Explained: Why the Ghost Haunted Claire

Harrison Ford and Michelle Pfeiffer in What Lies Beneath investigating the missing person photo

Throughout What Lies Beneath, Claire (Pfeiffer) is haunted by a female ghost, and at first believes it to be her neighbor, who's seemingly disappeared after a fight with her husband. However, the neighbor eventually returns, and it turns out this haunting is a lot more personal. The ghost is a young woman named Madison Elizabeth Frank (Amber Valetta), who was having an affair with Claire's professor husband Norman (Harrison Ford). As is often the case in horror, Norman and Claire's bright suburban existence was only a facade covering a dark reality, as not even a seemingly ideal marriage was enough to prevent Norman from cheating on his wife.

Since Madison is a ghost though, Claire quickly begins to suspect Norman was involved in her demise. Norman denies this, and being acted by Ford, he's pretty convincing, especially after Claire comes home to find him seemingly attempting suicide out of guilt over the affair. Alas, it's all a ruse, as Norman did indeed kill Madison, dumping her body in a lake, explaining why the haunting incidents kept revolving around water. Madison, Norman's student, had threatened to tell the dean at Norman's college about their affair

His dirty deeds exposed, Norman attempts to murder Claire too, but his plan fails, and the couple ends up in the lake, leading Madison to get revenge on her killer. While it's certainly been the message of more than one horror movie, What Lies Beneath's ending again reinforces the idea that secrets tend to get revealed, and crimes tend to get uncovered, and attempting to (sometimes literally) bury them only leads to worse problems for all involved.

More: Why Harrison Ford Is Angrily Pointing In Almost Every Movie