The real-life late ’60s fashion returned, as expected, on last nights episode of Mad Men. While we can always count on consistent, great fashion from the show, we were treated to a surprise: Don’s return to work.

Many were stunned to see him back in the office. Joan and Peggy were perhaps the most surprised, as they both greeted him with a snarky attitude. Joan, who met Don with a “well, I can’t say we missed you,” was wearing costume designer Janie Bryant’s favorite look of the night. “I love that dress. It was a vintage dress that I redesigned and made for Joan,” Bryant exclusively tells Instyle.com.

Peggy’s demeanor towards Don was just as icy as her baby blue suit. “It was just the perfect, perfect suit to describe Peggy Olson. I love that suit for her,” the costume designer says. Bryant fell for Peggy’s three-piece baby blue suit from the second she laid eyes on it. “I found the piece at one of my favorite vintage stores, Jet Rag, and it was one of those moments that when I pulled it out of the rack…the angels started singing. Seriously, because you know, you just don’t find those!”

Betty, who we got to see last night for the first time this season, also wore pretty pastels for episode three. Betty was in the same realm, attitude-wise, as Joan and Peggy: Her character was far from cheerful, but her looks were. “Betty is the image of perfection. It’s all about being appropriate and pretty,” Bryant tells us. “Betty is a character who is truly classic, she is a housewife and a politician’s wife. Betty always presents herself as an image of perfection,” she adds.

To see Betty’s look and more (including Megan’s California-girl style) from last night’s episode, browse through the gallery. You’ll find an exclusive tell-all on each look straight from costume designer Janie Bryant.