[Warning: The following contains MAJOR spoilers for Feud: Capote Vs. The Swans, Episode 3, “Masquerade 1966.”]

Feud: Capote Vs. The Swans brings the writer and his socialites together for a very special occasion in the season's third episode, "Masquerade 1966," as he hosts a black-and-white ball.

The event is based on a real party held over 50 years ago, and viewers are drawn into the excitement of it through the lens of the Maysles brothers, as the documentarians provide the framework that captures Capote’s (Tom Hollander) epic behind-the-scenes soiree. Similar to the black-and-white theme, much of the episode is also shot in the contrasting colors until the final moments when Capote’s mother (played by the mesmerizing Jessica Lange) takes to the dance floor, revealing a show-stopping all-black ensemble that is sure to rival all those seen in the minutes leading up to her unveiling.

But these stunning ensembles aren't your average designs, as fashion icon Zac Posen stepped into the metaphorical driver's seat for this epic on-screen journey, helping to curate key looks for the event. "It started as a dinner with Gus [Van Sant], the director, who's a good friend of mine. He was scouting locations and it led to a meeting with Lou [Eyrich] and then a chance meeting with Ryan [Murphy] in the food line at a dinner after an art show," Posen explained to TV Insider.