In celebration of the upcoming fifth and final season of Boardwalk Empire, HBO held a private affair Thursday night (Sept. 4) in New York City, dubbed “Boardwalk Backroom.”

Channeling Prohibition-era supper clubs and backrooms, it was a festive, thematic night of secrecy, a hint of danger and old-school elegance — featuring burlesque dancers and a secret performance from Boardwalk Empire’s Margot Bingham, which could only be accessed via a hidden entrance leading to Minton’s.

Following the performance, actor Michael K. Williams (Chalky White) gave a heartfelt speech about being entranced by Bingham’s voice when first hearing her sing on the set of Boardwalk Empire.

In addition to Bingham and Williams, the evening drew the likes of Valorie Curry (FOX’s The Following), Sam Underwood (The Following), DJ D-Nice, and Dick Parsons.

Attendees were treated to a host of signature prohibition influenced cocktails, delightful hors d’oeuvres, and a Boardwalk Empire-branded photo booth, while D-Nice provided the music.

The fifth and final season of Boardwalk Empire from HBO premieres this Sunday, September 7 at 9 p.m. ET/PT.