It may be that "Chuck," NBC's new comedy-action series, owes a part of its appeal to low expectations.

To appreciate just how low those might be, it's only necessary to know that the story concerns a computer geek who has trouble finding a girl, thanks to problems in the self-esteem department — and that this character's already beclouded mind is to become the repository for the top-secret files of U.S. intelligence agencies. To appreciate how well this nerd-within-the-CIA-and-NSA nonsense actually works out, it's only necessary to watch the panache with which the cast of "Chuck" carouses through the first episodes.

The Chuck in question, portrayed by Zachary Levi, holds a grim job at the Buy More computer store. He spends considerable time pondering his failures with women, his weaknesses and general lack of a place in the world — none of this the sort of thing that would make him an appealing figure. It's Levi who manages that — who imbues this character with a consistent, effortless-seeming charm that somehow never appears at odds with Chuck's hapless condition.

Chuck's worries about women soon give way to others far greater, which descend when he opens a subliminally encoded e-mail message that causes CIA and NSA files to imprint themselves in his brain. The result is often plain hilarious, and when not hilarious there is plenty that is engaging as expert hands carry off wonderful deadpan spoofs of martial arts and James Bond weaponry. One lovely battle between Chuck's CIA protector, Sara Walker (Yvonne Strahovski), and a deadly enemy takes place in a restaurant kitchen, where Sara is undercover as a chef — a struggle that employs a fabulous variety of weapons, among them all the food in the kitchen, including a French fried potato that Strahovski slings with convincing deadly force.

Chuck's other protector, NSA agent Maj. John Casey, is also undercover. As a worker in the Buy More computer store, he's subjected to all the vicissitudes of employment that clerks have to endure — including lectures on the use and nature of the price scanner. Adam Baldwin steals every scene as the menacing Casey. The price scanner must be treated carefully — it's an expensive piece of hand-held equipment, his store trainer, Chuck, instructs him. "So is a Stealth Fighter," the seething Casey can't help snarling. "But I somehow managed to fly that."

The writing is adroit, performances irresistible, the sheer fun of it all is unmistakable. Where this comedy by Josh Schwartz and Chris Fedak goes from here is hard to know, but it's among the brighter spots on the NBC schedule.

"Chuck" airs at 7 p.m. Mondays on NBC.