First 'Joker' Trailer Unveiled: Watch Joaquin Phoenix Transform Into The Iconic Batman Villain

Smile, and put on a happy face.

The first trailer for the forthcoming Joker movie has been released. Unlike previous films where the Joker is often explored and pitted against his archnemesis Batman, this one seems to explore the iconic DC villain against an increasingly worsening Gotham City, and how that contributes to Joker becoming who he is.

"My mother always tells me to smile and put on a happy face. She told me I had a purpose," Joaquin Phoenix, as Arthur Fleck, says as a beginning scene shows him in clown makeup and twirling a sign. At one point, a group of teenagers steal the sign, and as he chases them he's led down an alley and hit in the head with the sign by one of the teens.

From there, viewers get brief glimpses of Gotham City, particularly a scene in the Gotham City Hospital, where Arthur is in an elevator with a man strapped to a gurney screaming. These scenes lead back to Arthur, whose clown persona is slowly turning into something darker, the very last moments of the trailer showing Phoenix take on the Joker outfit with his own new spin.

Atlanta's Brian Tyree Henry and Zazie Beetz also make appearances in the trailer. The film also stars Robert De Niro, Frances Conroy, Brett Cullen, and Marc Maron. Before the trailer hit the internet on Wednesday, it was premiered at CinemaCon, where people present tweeted about the trailer and gave their thoughts on it.

Todd Phillips, the director of the upcoming movie, called Joker an "origin story about a beloved character with no definitive origin," and said the genre of the film is "tragedy," at CinemaCon.

Joker will be released on October 4.