Helen Mirren and her director, Bill Condon, delivered one simple message as they promoted their upcoming thriller THE GOOD LIAR at CinemaCon 2019 in Las Vegas: Protect the ending at all costs.

Condon, whose previous films include the musicals CHICAGO and DREAMGIRLS, as well as the OscarÒ-winning GODS AND MONSTERS, warned the crowd from the stage that the ending of THE GOOD LIAR is so significant to the success of the story that he feels like it needs to be shrouded in secrecy for the benefit of anyone who wants to come see the movie.

There’s a chance you might know the ending already, however. THE GOOD LIAR is based on a best-selling book by Nicholas Searle, released in 2016. And Condon told the crowds at CinemaCon that he knew he needed to turn “The Good Liar” into a movie the moment he read the bombshell ending of the book. The movie is due to drop in theatres on November 15.

We were treated to the first full trailer for THE GOOD LIAR, and it established a mesmerizing cat-and-mouse game between Helen Mirren and Ian McKellen. He plays an aging con man who marks a wealthy widow (Mirren) as his next target. The closer that he gets to her, however, the more emotionally attached he becomes … and we all know that nothing good can come of that.

The comparison that Bill Condon made about protecting the film’s shocking ending was one that caused us to sit up straight and pay closer attention. He compared it to PSYCHO, Alfred Hitchcock’s staggering masterpiece. You may have heard that when PSYCHO reached theatres in 1960, the marketing campaign — led by Hitchcock himself — begged those who had seen the movie to guard the final reveal from anyone who had yet to see it. And for a while, audiences were barred from entering the theatre if they missed the opening 15 minutes of the movie.

In today’s day and age of social media and instant online reviews, preventing spoilers for THE GOOD LIAR will be more difficult. But at the very least, it sounds like Condon, Mirren and McKellen have a twisty and engaging adult thriller on their hands, and now we can’t wait to see what they will share with us in November.

Look for THE GOOD LIAR when New Line Cinema puts it into your nearest AMC on November 15.