On the set of ''Saw II''

Darren Bousman stands over the crumpled body of a wounded policeman, simply thrilled. This morning, the Saw II director gets to decide how this poor sap and his SWAT team homies fall prey to the gruesome machinations of one Jigsaw Killer.

”We’ve got some leg breaks happening today?” asks Bousman, consulting his ponytailed special-effects guru, Francois Dagenais.

”I thought we were going to have him crawl through the puddle of blood,” Dagenais reminds him.

”Oh yeah, that’d be great.”

Bousman’s in heaven. Just last year, his résumé boasted only commercials and videos. Now he’s helming the follow-up to Saw, the low-budget horror flick from Aussie upstarts Leigh Whannell and James Wan that cost a meager $1.2 million to make and went on to gross 100 times that worldwide.

Twisted Pictures producers Greg Hoffman and Oren Koules were thinking sequel before Saw was even released, but writer-director Wan and writer-costar Whannell were already committed elsewhere. When the producers stumbled upon an original screenplay the 26-year-old Bousman had sent in on spec, they decided it would make a great basis for Saw II.

”You spend a lot of time working on something and you envision it one way,” says Bousman, ”so it’s always a jolt when you find out they’re going to take it and morph it into something else. But there was so much press around Saw, so it was a huge honor.”

Although Saw II was adapted from Bousman’s ideas, quarterbacking the fledgling franchise hasn’t exactly been a blood-soaked free-for-all for the newbie director. ”His original script was really brutal,” says Hoffman. ”He likes action and hardcore, but I don’t think you need to add buckets of blood to what’s already an edgy concept.”

The first Saw was more suspense, sadism, and what Dagenais calls ”implied violence” than actual gore. Jigsaw, the serial killer played creepily by Tobin Bell, doesn’t so much murder people as force his victims to make deadly choices. Whannell made sure Bousman didn’t stray far from the formula. ”I pretty much came in and completely rewrote it from scratch,” he says. ”And Darren was cool with that.”

Bousman had to keep costs low as well. ”You feel like you’re on a soap opera set instead of the sequel to a movie that made $100 million,” says Donnie Wahlberg, who plays stressed-out cop Eric Mathews. ”You’re like, ‘Damn, you’d think they could build a real wall.”’

”It’s still a tight show,” confirms Hoffman, who won’t reveal the budget. ”The big mistake is to make that little indie movie and then go, ‘Oh, we’ve got to throw $25 million at the next one.”’ But Bousman wasn’t completely handcuffed. Thanks to webloggers clamoring to see more of Jigsaw’s death traps, the bloodthirsty director got to shed plenty of plasma in this one while still pulling off enough reversals to satisfy at least one customer. ”I wanted to see if they could make me say ‘Oh, s—!’ at the end,” laughs Wahlberg. ”And they did. I said it twice.”