Shutter Island water glass scene gives away whole plot twist of movie if you watch closely

Shutter Island was released in 2010 but viewers are still left in awe at the film's memorable plot twist.

Starring Leonardo DiCaprio alongside Mark Ruffalo, the film follows U.S Marshal Teddy Daniels (DiCaprio) as he investigates a missing patient at a psychiatric hospital.

However, the story turns the viewer's expectations on their head with one of the most mind-twisting endings in history - if you know, you know.

But apparently, there was a scene early on in the film that supposedly gives the ending away.

If you haven't seen the film yet, a) you should go and watch it, and b) spoilers ahead!

The psychological neo-noir film, based on the novel of the same name, shows numerous flashbacks of Teddy's history throughout the film but it is not made very clear.

We then find out at the end of the movie that Daniels is, in fact, a patient at the institution himself (I'm still not over it), who was sent there after killing his manically depressed wife who drowned their children.

Paramount Pictures

The 'missing patient' idea was something thought up by Daniels to deal with the death of his family.

Staff at the asylum go along with it to see if it will help him finally accept what has happened before deciding to lobotomise him.

Teddy's true history wasn't exactly hidden to the audience, however - with some pointing out a particular prop used by Daniels actually gives away the huge plot twist.

Now, there is a scene earlier on in the film that people think does the same thing.

In a scene where Daniels speaks to one of the patient's from the victim's group therapy session, the glass of water she asks for disappears when she takes a drink from it.

Paramount Pictures

And it is thought that the reason for this because we are looking at the scene through Daniel's eyes, who has a deep-set trauma with water after the death of his children.

They do say hindsight is 20/20.

And viewers shared their thoughts on the scene on YouTube, with one saying: "I F**KING KNEW IT"

Another commented: "And I think she did that on purpose trying to get him to realize something was wrong"

A third put: "I thought that i had watched it wrong lol"

While a fourth said: "Damn."

The movie really is a mind-boggler but that's what good psychological films do, right?