“Joker: Folie à Deux” is the No. 1 movie at the box office, but it might not be destined for a happy ending. In a turn of events that only Arthur Fleck would find funny, the follow-up to Todd Phillips’ 2019 origin story about the Batman villain opened in theaters nationwide this weekend to a muted $40 million, according to studio estimates Sunday, less than half that of its predecessor. The collapse was swift and has many in the industry wondering: How did the highly anticipated sequel to an Oscar-winning, billion-dollar film with the same creative team go wrong? Just three weeks ago, tracking services pegged the movie for a $70 million debut, which would still have been down a fair amount from “Joker’s” record-breaking $96.2 million launch in Oct. 2019. Reviews were mixed out of the Venice Film Festival, where it premiered in competition like the first movie and even got a 12-minute standing ovation. But the homecoming glow was short-lived, and the fragile foundation would crumble in the coming weeks with its Rotten Tomatoes score dropping from 63% at Venice to 33% by its first weekend in theaters. Perhaps even more surprising were the audience reviews: Ticket buyers polled on opening night gave the film a deadly D CinemaScore. Exit polls from PostTrak weren’t any better. It got a meager half star out of five possible. MORE: https://www.wthr.com/article/news/nation-world/joker-2-box-office-opening-amid-poor-reviews/507-0e089053-612e-4a64-9469-df1e03a2e0f1