Earlier this month, fans got their first look at the impressive Murder on the Orient Express cast with new photos. Tomorrow, you'll finally get to see this massive ensemble in action! 20th Century Fox will be releasing the first trailer Thursday morning. But until then, the studio has unveiled the poster, which also features a hidden clue as part of an ongoing viral campaign where fans will try to unravel this mystery at CluesAreEverywhere.com. If that wasn't enough, actress Penelope Cruz and star/director Kenneth Branagh shed some new light on this adaptation of Agatha Christie's classic tale.

People debuted this new poster and spoke with Penelope Cruz, who plays Spanish missionary Pilar Estravados. The actress revealed that she was drawn to this project because each of these characters are so mysterious. Here's what she had to say below.

"The characters, all of them, have so many layers and so many colors. It's hard to know, 'Oh, this is obviously an innocent person and this is obviously the guilty person.' It's very ambiguous the whole time because that's what human nature is."

The enormous ensemble cast includes Kenneth Branagh, who both directs this adaptation and stars as Agatha Christie's iconic detective Hercule Poirot. Poirot tries to decipher this murder mystery aboard the iconic train, which runs from Istanbul to Paris. The rest of these characters are potential suspects, such as Johnny Depp's Edward Ratchett, Michelle Pfeiffer's Caroline Hubbard, Manuel Garcia-Rulfo's Biniamino Marquez, Daisy Ridley's Mary Debenham, Leslie Odom Jr.'s Doctor Arbuthnot, Olivia Colman's Hildegarde Schmidt, Judi Dench's Princess Dragomiroff, Sergei Polunin's Count Andrenyi and Josh Gad as Hector MacQueen Josh Gad's Hector McQueen, Derek Jacobi's Masterman, Willem Dafoe's Gerhard Hardman, Lucy Boynton's Countess Andrenyi, Marwan Kenzari's Pierre Michel and Tom Bateman's Bouc. While the story is still set in the 1930s, like the original Agatha Christie story, the actor-director revealed he wanted to choose a diverse cast and focus more on the plot's "dark edge."

"(Murder) is a deeply uncivilized act and it unleashes in its execution the primal, the primitive, the atavistic, and that's a very dangerous force and it's right underneath this piece. So that I think that we stayed further away from drawing-room mystery in the sense of a board game, and more into this kind of terrifying encounter with danger and death."

Kenneth Branagh directs from a script by Michael Green (Blade Runner 2049), based on Agatha Christie's 1934 novel. The book was originally adapted into the 1976 movie of the same name, which starred Albert Finney as Poirot and featured an Oscar-winning performance from Ingrid Bergman. Murder on the Orient Express will go up against Daddy's Home 2 and The Star. Take a look at the new poster for Murder on the Orient Express, and check back tomorrow morning for the first trailer.