Alexander Wang had a surprise up his T-shirt sleeve on Saturday night. The designer, who often throws epic after-parties postshow, most featuring performances by hip-hop icons, ended with another kind of bang. After the last model took the runway, a video, shot like murky security camera footage, revealed dark hoodies featuring a familiar logo. Then, models stormed the stage in activewear featuring the Adidas trefoil turned upside down. Boom! Just like that, the designer debuted his new hush-hush collaboration with Adidas Originals. Here’s everything that went down.