Carnival has many rituals, but only one that makes the sky explode. That happens on the night before Mardi Gras, now more familiarly known as Lundi Gras, and the setting is the stage at Spanish Plaza right alongside Riverwalk.

Since 1987, Rex has arrived there, originally on a Coast Guard cutter, to greet the crowd. Beginning in 1999, the monarch has had a visitor, King Zulu and his entourage. The black and white of it is that two monarchs, sometimes thought to be representing separate parts of the universe, are backslapping and cheering on Lundi Gras afternoon. Nearby is the mayor. There have been five different chief executives since the tradition started and all have been eager to be part of the show. The big moment comes when the mayor is asked to concur with a proclamation issued by Rex asking that schools and businesses be closed the next day so that the polity can enjoy Mardi Gras Day without fear of the local gendarmes. To date, every mayor has concurred, giving civic backing to the royal wish list. And this is where Carnival’s finest moment occurs. A contraption with a raised handle is placed before the empowered three. Each grabs hold to a part of the handle prepared to push it down at the proper moment.  Toward that moment the excited crowd yells the countdown “Ten, nine, eight, seven, six…”

In a season filled with royalty there are many moments of scepter-waving, and kings and queens bowing to each other. One of the most famous moments happens Mardi Gras night when Rex and his queen greet Comus and his consort. In a moment laden with symbolism, the King of Carnival, who is celebrating his 150 anniversary this year, acknowledges Comus, who in 1857, started the parading tradition that would characterize the city. In the world of rituals, the “Meeting of the Courts” is hallowed as monarchs from antiquity honor each other. To get there though, there was the countdown from the night before.

“Five, four, three, two, one…” Down goes the plunger powered by two kings and the mayor. And then the sky is filled with rockets’ red glare, and the colors of the spectrum. Blasting from the loudspeaker are the infectious rhythms of New Orleans’ indigenous rhythm and blues carnival medley. Rex, who on the next night will be promenading to Giuseppe Verdi’s “Grand March from Aida,” is, for the moment, boogieing to Profess Longhair’s “Going to the Mardi Gras.”

If only the moment could be freeze-framed, as rulers and their subjects celebrate Carnival’s only fireworks show, brightening the night with the message that Mardi Gras, the day, is arriving. The sky is filled with splashes of many colors.

And the moment itself is pure gold.