“I didn’t realize it was live! I thought they just tape it,” Mr. Grenier told the Transom, who had arrived there in true Vincent Chase (read: fashionably late) form.

The casual cocktail hour and screening was for a small group of HBO friends, employees and a few cast members. (Mr. Grenier and Kevin Connolly, who plays Vince's best friend and manager, were present, but Kevin "Johnny Drama" Dillion and Jerry "Turtle" Ferrara were missing from the entourage.)

Mr. Grenier and Mr. Connolly were dressed so similarly to their characters that the Transom had to wonder just how much these guys are like their characters.

Mr. Grenier was wearing, for example, a very Vince-esque white crew-neck T-shirt, a gray zip-up sweater, gray dress pants and dark sneakers. Mr. Connolly wore a white button up shirt and an unbuttoned blue suit, sans tie.

But, aside from their clothes, not much else about these guys seemed like the ones they play on TV.

For instance! On Entourage, Vince just got his license, even though he's a terrible driver. But Mr. Grenier has been driving since he was 15.

“My mother taught me how to drive in the Ithaca hills on a stick!” Mr. Grenier said. Impressive!

And while Vince, in the time between last season and the current one, has wrapped the Martin Scorsese remake of The Great Gatsby (oh if only this were real life!) and moved back to Hollywood, Mr. Grenier, a born and bred New Yorker, vowed to the Transom that he would never leave New York.

Mr. Connolly, who is less devoted to the East Coast, traded in his subway pass for a car to cruise along Santa Monica Boulevard a long time ago.

“I have a decent car,” he said,  “but I can’t top the ones on the show. There aren’t any nicer cars than those.” (Now that Mr. Grenier's Vince is playing Enzo Ferrari in a bio pic, everyone in the gang is driving a sports car of his own, including Turtle!)

Last night, the boys seemed to roll on a much lower profile. Mr. Grenier went to the bar to get his own drink and was not afraid to be seen standing solo in the room. Mr. Connolly had a very scruffy red beard, which he told the Transom he never gets to grow because the first thing he gets on set every day is a shave.

When the night ended, Mr. Grenier (with a rugged navy backpack thrown over his shoulder) exited the building and headed down Fifth Avenue, on foot.