The official teaser trailer for Todd Phillips' Joker is set to drop tomorrow, but those who attended CinemaCon were lucky enough to get an early look at the footage.

The film will serve as an origin story for Batman's most famous villain, but aside from several set photos and clips, not much is known about the movie. Phillips told the audience at CinemaCon that the film will be a tragedy, which is pretty evident from the description of its first trailer.

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The footage opened on Arthur Fleck in therapy as he describes caring for his sick mother, where he also experiences a flashback in which he's washing his mother. He says to the therapist (Zazie Beetz), "My mother always tells me to smile and put on a happy face. She told me I had a purpose, to bring laughter and joy to the world." The trailer showcases Arthur's descent into madness, featuring footage of him forcing a smile with his hands in a mirror, laughing to himself on the Gotham subway and running around in full clown makeup.

The most exciting thing about the trailer is the audience got a preview of Phoenix's take on the Clown Prince's iconic laugh. While attending a comedy club, Arthur Fleck laughs, but appeared to be the only one laughing.

The trailer also featured another famous Gotham citizen: Thomas Wayne (Brett Cullen), aka Bruce Wayne's father. Wayne is on a TV program discussing the Joker, saying, "Gotham has lost its way." Wayne also calls the Joker a coward for hiding behind a mask, which is interesting considering who his son becomes. The trailer ends with the line, "I used to think my life was a tragedy but now I realize that it's a comedy," with the footage closing on Aruthur in the clown makeup and a red suit.

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Finally, the usually pleasant song, Smile by Nat King Cole, gave the trailer an eerie tone when juxtaposed to Phoenix's clownish antics.

Directed by Todd Phillips, Joker stars Joaquin Phoenix, Robert De Niro, Zazie Beetz, Frances Conroy, Brett Cullen, Dante Pereira-Olson, Douglas Hodge and Josh Pais. The film arrives in theaters Oct. 4.

(via Screen Rant)