How do you celebrate the hotly anticipated second season of your hit Netflix series? If you are the cast of Stranger Things, you have a Halloween-themed premiere, complete with a haunted carnival, a spooky graveyard scene, and, of course, plenty of Eggos. The entire Hawkins crew—including Millie Bobby Brown, Winona Ryder, and newcomer Sadie Sink—were in attendance, kicking off Halloween in style. Elsewhere, Cole Sprouse‘s twin brother Dylan joined Billie Lourd at the opening of American Eagle’s new flagship in New York, Miles Teller debuted his new film Thank You For Your Service, and Julianne Moore hosted a dinner to celebrate her new campaign for John Hardy. Also making the rounds this week: Olivia Wilde, Zachary Quinto, Rebecca Dayan, and Blondie, among others. Here, take a look at the best party pictures of the week.