Behind the scenes of ''Oz''

Welcome to the wonderful world of Oz.

”Bring me a gallon of blood!” a crew member bellows as Sean Whitesell, a straggly-haired actor who looks like a cross between Jesus Christ and Ted Nugent, is strapped into a wooden chair. Whitesell’s Oz character murdered his parents, ate his mother, and saved his father in the freezer for Thanksgiving. Now he’s about to be executed by firing squad. Another crewman rushes in with a tube of Reel Blood — a mix of corn syrup, food coloring, and detergent — and squeezes it onto Whitesell. ”Bloody him up,” the crew chief says. ”We’re making him dead.”

Nope, we’re not in Kansas anymore, Toto. We’re inside the fictional Oswald Maximum Security Penitentiary — and deep inside the mind of Tom Fontana, creator of Oz, HBO’s first hour-long dramatic series (debuting July 12 for an eight-week run), as well as a veteran of the acclaimed NBC dramas Homicide: Life on the Street and St. Elsewhere.

For his first foray into the uncensored world of pay-cable, Fontana has let his imagination run wild — really wild. In its superrealistic depiction of prison life, Oz features graphic violence, full-frontal male nudity, and enough blue language to make Sipowicz blush. ”The things I’m getting away with, I should be arrested for,” says Fontana gleefully. ”I’ve told my 75-year-old Italian-American mother she can’t watch the show. She’s going to be the oldest person on the planet with a V-chip.”

Fontana — sporting a T-shirt with a picture of a dog licking its own genitalia, under the banner ”Because I Can!” — is clearly relishing the freedom from network-TV concerns. ”Instead of getting calls saying ‘Can’t they hug each other at the end?’ I’m getting ‘Just go a little further, a little edgier,”’ marvels Fontana. ”I feel so unleashed.”

The idea for Oz developed as Fontana grew frustrated with the networks. ”I had tried to sell several ideas to various networks, all of whom spit in my face,” he jokes of such failed pilots as ABC’s Philly Heat, CBS’ Firehouse, and NBC’s The Prosecutors. ”We took Oz to HBO, and they embraced the idea because they’d had success with prison documentaries and movies, so they thought they had an audience for this.”

The violence and profanity inherent in the genre — not to mention the difficulty in finding a place to shoot such a show — are no doubt big reasons why there’s never been a successful prison series on network TV. For Oz, using a working prison was ruled out (partly because it’s too time-consuming getting equipment through the metal detectors), and there are precious few nonworking houses of detention. ”Because we have such a great criminal justice system, we’re full up,” quips Fontana. So HBO built a sprawling faux prison inside a warehouse on the border of Manhattan’s meatpacking district. Though its cinder blocks are actually made with Styrofoam, Oz‘s set — complete with cells, guard stations, cafeteria, laundry, and weight room — is oppressively realistic. And shooting almost entirely indoors only adds to the feeling of claustrophobia. ”It’s like time stops when you walk in here,” says New York Undercover‘s Lauren Velez, who plays the prison’s doctor.