I was told at 3:43 in the afternoon, roughly five hours before the scheduled start of 12 Angry Mascots, a sports-comedy show I co-write/produce at Gotham Comedy Club, that Jerry Seinfeld would be doing an unannounced set during our performance. Word came from my writing partner, Scott Rogowsky, who doubles as host of the show. He had been at the venue setting up when Gotham’s GM pulled him aside and told him to clear room in our run list; Jerry wanted to try out some material. (We later learned he was testing out jokes before appearing on Letterman the following night.)

Then I was told I not to tell anyone. As comedy code dictates, you don’t issue an APB when established comics swing by to experiment. You let them work in as normal an environment as can be created to get as honest a reaction as can be expected. But Jerry Seinfeld, as you may know, is a comedian with whom a great deal of people have a great deal of familiarity. Our show, as you can’t possibly know, rarely draws the tens of thousands of people it deserves, or more than 80. Using the former to draw people to the latter would have been a desirable arrangement. We were told not to do so. We wanted Jerry Seinfeld to come to our show. We obeyed.

From that point on, the night had a Waiting For Godot-like air about it. Seinfeld’s appearance wasn’t guaranteed, but we had to nevertheless plan for it. That meant killing a couple bits, restructuring the show and, as they each arrived, instructing our performers to play it cool because Jerry Seinfeld was going to be performing, yes, tonight, on our show, seriously, we’re not fucking with you, yeah, Jerry Seinfeld. Our featured comedian, Wayne Federman – a funny and, as we came to learn, understanding comic and human being – was the last performer to arrive, punching in around 8:15. We typically have our comedians perform in the third act of our show (since you’re jonesing to know, the first act is monologue and topical fare; the second sketches and character bits, the third a comic performance and athlete guest interviews), but since Seinfeld said he’d be coming around 9:15 – right at the top of act two – and we didn’t think it fair to ask Wayne to follow Seinfeld, we told Wayne he’d actually be going up much earlier in the show. He was fine with it. He’s a very understanding person.

The show began at 8:30, and with nothing to do until the penultimate bit, I stationed myself at the back of the room near the tech booth. Just after nine Seinfeld arrived. From where I stood I could see his head peeking through the windows of the showroom’s double doors. The GM and floor manager greeted him, and then two of our producers, Kim O’Hara and Hilary Siegel, went to find out how things were going to go. Kim came back with a grin that explained her giddy trembling; Hilary came back and told us how things were going to go: As soon as the current bit (a wonderful number about a racist academic who views Native American mascots as propaganda for a forthcoming Indian insurgency) concluded, Jerry was going to go up. That’s how things were going to go. Our scheduled bits would have to wait. Wayne would have to follow Seinfeld. Jerry was in the hallway.

Hilary ran around the showroom and knelt in a shadowed nook until the end of that hysterical racist sketch, at which point she told Scott It Was Time. Scott gave little introduction beyond telling the crowd that a special guest had stopped in, and then, with uncharacteristic subtlety, welcomed Jerry Seinfeld. Seinfeld took the stage amid more applause than we’ve cumulatively generated in two years of sports-comedy variety talk shows. We had been instructed by the floor manager to tell our cameramen, as well as those with the media, to turn their cameras off and away when Seinfeld took the stage, but that proved pointless. As their lenses dipped downward, a squadron of cell phones rose out of the crowd and hovered in the air for the duration of the set. Our cast of performers, who usually chat quietly throughout a show from the back tables, sat silently. The tech guys stepped out of the sound-obscuring booth. The club shut off the lights nestled into the ceiling above the windowed hallway that runs behind Gotham’s showroom. No one would be using it.

When Seinfeld got on stage he noticed the cloth-covered desk at which Scott sits while hosting, and asked if this was some sort of talk show. If anyone answered, the response wasn’t audible from the back of the room. Scott, who usually remains at his desk while comedians perform, had negotiated the darkened hallway to watch Seinfeld’s set from our vantage point. The lights were down, the cell phones were up and the room was quiet.

Then Jerry Seinfeld began to tell jokes. He told jokes that were safe and expertly crafted for a mainstream audience, and if a comic without Seinfeld’s experience and delivery and name had told them, they might have bombed. He told jokes about Five-Hour Energy. He told jokes about car commercials. He pulled a folded piece of legal-sized yellow paper from his jacket pocket and scanned it for more jokes to tell. Then he told those jokes – ones about email, and Pop Tarts. Every joke he told killed. After 15 minutes of new jokes, he calmly asked the crowd if they had any questions for him, fielded a few of them, and then left to a partial standing ovation. Through the windows of the showroom’s double doors we watched him say goodbye to the GM, walk down the hallway past the photo of himself that hangs on the wall, and out to his car.

The dust settled, and our show continued as planned. I’m told it was hilarious.

Neil Janowitz is an editor for ESPN the Magazine and co-founder of sports-comedy outfit 12 Angry Mascots. He has lots of Twitter accounts.

What It’s Like When Jerry Seinfeld Crashes Your Comedy Show