It’s the year of the big-box comedy. For those keeping score, two of the new season’s more promising series, “Chuck” (7 p.m., NBC) and tomorrow night’s “Reaper,” involve everyday dudes making barely minimum wage at an enormous mall store who find their lives transformed by fantastic events beyond their control.

“Chuck” stars Zachary Levi as Chuck Bartowski, a bright but unambitious clerk and computer-repair geek who works at the local electronics superstore. His moment of transformation arrives in the form of an e-mail sent to him by a former roommate and rival from Stanford. Chuck’s old pal had been stealing secrets from the CIA and embedding them in mind-blowing images. Once Chuck sees these missives, all of the secrets of America’s intelligence agencies are downloaded into Chuck’s seemingly normal brain, making him a wanted man – by the good guys, the bad guys and everybody in between.

Washington dispatches agents to shadow Chuck, including the fetching Sarah (Yvonne Strzechowski), who poses as Chuck’s new girlfriend, the first he’s had in years. Joshua Gomez rounds out the cast as Chuck’s needy and nerdy pal Morgan, who has no idea of his new predicament.

“Chuck” does a good job of mixing the mall shenanigans of “40-Year-Old Virgin” with the thrills of “24.” It’s nice to see the life-or-death conceits of espionage become funny again.

l “The Big Bang Theory” (7:30 p.m., CBS) is so obvious it just might work. Two math wizards, Leonard (Johnny Galecki) and Sheldon (Jim Parsons), find their lives transformed when the vulnerable, pretty Penny (Kaley Cuoco) moves next door. Anyone who has ever watched “Bringing Up Baby” knows the notion of a brain falling for a beauty is hardly new. Sadly, the writers of “Bang” mess up a potentially sweet situation with an onslaught of crude jokes.

l Meanwhile, on “Journeyman” (9 p.m., NBC), ace reporter Dan Vasser (Kevin McKidd, “Rome”) is a decent guy with a great wife (Gretchen Egolf) and nice kid (Charles Henry Wyson). Unfortunately for Dan, he seems to be unstuck in time. For reasons unexplained, he keeps bouncing into the recent past, landing without explanation in 1987 and 1989, where women have big hair and smart alecks read Spy magazine.

Dan has a heck of a time understanding all of this and an even harder time explaining his absences to his wife and boss. These quantum leaps also put him in intimate proximity to his old fiancee (Moon Bloodgood), now dead, leading us all to creepy thoughts and implications. Things get stranger when the 2007 version of Dan crashes a dinner party in the place of 1989 Dan and nobody seems to know the difference.

Given its ponderous tone and baffling plot, I don’t think “Journeyman” has much of a chance of surviving 2007.