Over the past few years, USA Network has been perhaps the most progressive cable channel when it comes to producing original, weekly series.

The key ingredient for USA has been suspense. First came its “Sunday Night Heat” lineup, built around “Silk Stalkings,” a CBS refugee that has become the longest-running dramatic series on cable. It returns for its eighth season July 26.

Now USA is building a second night of original programming. “Saturday Night Heat” debuts Sunday, July 19, moving to its regular time slot on Saturday, July 25. The two new shows are “The Net,” at 9 p.m.; and “Sins of the City,” at 10 p.m.

“The Net,” based on the 1995 film starring Sandra Bullock, promises to be the better of the pair. That’s mainly because it’s plot-driven rather than largely depending on atmosphere.

Angela Bennett, played by “Melrose Place” alum Brooke Langston, is an unusually attractive computer nerd. She’s a free-lance programmer who fixes glitches in software from her isolated aerie, and her only friend is her kindly ex-con bookkeeper.

Then she accidentally receives an e-mail that she isn’t supposed to see. Before long, her identity has been erased from all computers. Instead, she has become a wanted criminal who’s on the run, trying to take back her life.

You see, Bennett has crossed paths with the Praetorian Guard, whose mission it is to take over the world by creating chaos through technology. Her only ally is a mysterious voice she met online known as Sorcerer (voiced by Tim Curry). So Bennett seeks to bring down the Praetorians, armed only with her trusty, voice-activated laptop, while staying ahead of the group’s key operative, Trelawny (Joseph Bottoms) and his henchpersons (how very PC).

Now, shadowy, quasi-governmental agencies are very much in vogue (see “X-Files,” “Millennium,” “The Pretender”). But the cyberespionage angle gives “The Net” a somewhat fresh approach.

Langston does an admirable job in assuming Bullock’s role as the plucky, levelheaded heroine who’s at home on the Net. As the pistachio-chomping villain, Bottoms creates a multidimensional character who can both charm and chill. Any show that only uses the voice of the scenery-chewing Curry is missing a golden opportunity, but this is cable. Budgets are small, and so are casts as a result.

The other USA rookie, “Sins of the City,” offers an intriguing concept as well. Vince Karol (Marcus Graham) plays a private detective who as a cop got pushed off the force after being framed for an indiscretion.

“Sins of the City” is a whydoneit instead of a whodunit. Karol goes beyond just solving crimes, as he’s more concerned with the motivations behind the acts.

A good idea for a series (cop as psychologist, cop as confessor), but so far, Graham appears to be a graduate of the early Eastwood School of Acting. His facial expressions range from sullenness to a pained grimace that passes for a smile. Sure, the character’s life is in the crapper, but lighten up, already!

Also, the rest of the tiny cast is similarly stereotyped. Jose Zuniga (from the cruelly short-lived “Nothing Sacred”) plays Freddie Corillo, Karol’s emotional Cuban friend on the force, while Barbara Williams plays Sam Richardson, a world-weary lawyer who is Karol’s confidante.

The series is set in Miami, but “Sins of the City” fails to employ the distinctive vistas nearly as well as the groundbreaking “Miami Vice.”

“Sins of the City” will rise and fall with the strength of each episode’s writing. Should Graham be allowed to show more range, the series could well improve and be worth watching on a weekly basis.

So, the two new series rank far below USA’s stylish, moody “La Femme Nikita.” They would be on a par with the lamer, latter-day “Silk Stalkings” and the late “The Big Easy” but are superior to the Baywatch-on-bikes amalgamation that is “Pacific Blue.” In any event, both are an interesting way to pass a slow, summer Saturday night. They certainly beat the paint-by-numbers scripts of “Walker, Texas Ranger.”