Exclusive: Dîner en Blanc is back in D.C.

Fancy flash mob picnic party Dîner en Blanc returns to D.C. on Saturday, September 21.

Why it matters: Love it or love to hate on it , the globetrotting fête is always hugely popular and attracts thousands dressed in their blanc best.

How it works: The all-white party, which started in Paris in the '80s, thrives on mystery. A location is revealed the day of — typically somewhere huge and photogenic, like the National Mall — and ticketholders flock to the setting with everything for a grand feast (BYO tables, chairs, oysters, decorative birds , etc.)

• Entry tickets ($52 per person) are available in phases. First, members who previously attended can sign up on July 18. Their guests and sponsors can follow on July 23. Newbies can join a "fan list" and register on July 25.
• A $14 annual membership fee is required at the time of ticket purchase.

New this year: A later, potentially cooler date. Event co-organizer Kaitlin Davis tells Axios that they're focusing on more entertainment and "the guest experience" this year with a well-known DJ, dueling piano players, and theatrical entertainers.

Zoom out: Dîner en Blanc visits roughly 80 cities worldwide and launched in D.C. in 2014.

Zoom in: To throw a uniform party for around 4,500 guests, the organization sets some guidelines .

• Everything is white (no cream, please).
• Dress and food/drink follow elegant themes (wine and Champagne only, no beer or booze).
• A penchant for sparklers and napkin-waving is indulged.

What they're saying: It's all about mingling. "You may sit next to someone you don't know when you arrive, but by the end of the night you're exchanging numbers and making plans," says Davis.