Earlier this week, the London unveiling of the newest installment of the Harry Potter franchise, Harry Potter and the Half-Blood Prince, was a wet affair: an estimated three days' worth of rain hit the British capital in a single hour, drenching the stars as they arrived. Last night, though, New York City provided a very different reception: a sunny, surprisingly cool summer dusk ensured that the strip outside the Ziegfeld Theatre was awash with fans screaming and clambering over barricades and parked cars for a glimpse at their Potter-world icons, Emma Watson, Daniel Radcliffe, and Rupert Grint. "Now that's a welcome," Watson, in a Proenza Schouler minidress, said. Inside the theater, some fans were a little too dedicated to getting their shots, even trailing celebrity attendees into the restrooms with their digital cameras. Not that Watson was fazed: "I'm wearing a leather dress, so I'm feeling pretty tough tonight."

Following the premiere, red double-decker tour buses chauffeured guests to the American Museum of Natural History for the film's after-party. The entrance was lined with mist, the buffets were set up to look like the Weasley boys' magic shop, and a quidditch field had been constructed outside on the lawn. For Radcliffe, Grint, and Watson, this was just another stop on the Harry Potter express. With the seventh and eighth movies filming this year (J.K. Rowling's last book will be split into two installments) and a theme park rumored to be in the works, it looks like Harry and co. will be busy until all of them are well out of their teens. "It's a scary thought," Radcliffe acknowledged. "But a fun one, too."

Plus: How Emma Watson became fashion's newest darling >

— Derek Blasberg