All My Children star Josh Duhamel exited the ABC sudser last October, when his Leo du Pres character "drowned" in a waterfall's raging rapids. He returns to TV in NBC's Las Vegas — debuting Sept. 22 at 10 pm/ET — as a casino security pro who charms the ladies. But the 30-year-old heartthrob hasn't forgotten his soap-opera roots. The fans won't let him!

"Because [we shoot in] Vegas, they feel free to do anything," says Las Vegas creator Gary Scott Thompson. "On our first night of shooting, we had Josh on Fremont Street in a car. It was St. Patrick's Day, and as the night got longer, the drunker people got. By the end of the night, there was 20,000 of them, at least, screaming his character's name from All My Children. 'Why did they kill you, Leo? Leo!'"

Duhamel — who says "Leo is a part of me" — has come to expect gawking tourists at work. This season of Las Vegas wasn't filmed exclusively on a closed-off Hollywood set, but right in the heart of real, live casinos Mandalay Bay and the Palms. "They don't actually shut down the casino," he says. "They just shut down a little corner of it, so it's almost like we're monkeys in a cage at some points, because it's a huge casino, and they're not going to shut down the traffic of the patrons. They bring a lot more money in than [we do]."

But back to the ladies. Among Duhamel's female admirers in the pilot is Molly Sims, with whom he hits the sheets. When the actress got nervous about their simulated sex scene, he lightened things up, in his typical goofy way. "I said, 'If something happens down there, I'm sorry. And if something doesn't happen, I'm sorry.'"