Fans of AMC's critically acclaimed show Mad Men don't have to wait much longer! The drama-filled program set in the late-1960s world of Manhattan advertising firms makes its epic return to the airwaves tonight at 9/8c. When we last left Don and Megan Draper, Joan Holloway, Peggy Olson, and the rest of the crew from advertising firm Sterling Cooper Draper Pryce, Don was sitting in his most natural habitat, suggesting a return to his pre-Megan, philandering ways: at a bar, being approached by an attractive woman, while Megan shoots a commercial in the background. He and Peggy had mended their relationship after reuniting randomly in a movie theater, Pete and Beth (real-life fiancés!) ended their affair, and Roger continued his own. But more important than all this: in season five, the fashion evolved from early-60s era retro to late-60s disco-infused looks. Emmy-winning costume designer Janie Bryant talked to InStyle.com about the season's best looks and why she loved them. Click through the gallery below to find out why! And tune in to AMC tonight at 9/8c to catch all the action as it unfolds.