New York — Tom Fontana lives with souvenirs from TV series he has brought to life.

In a corner of his office stands the marble statue (really fiberglass and hollow) of St. Eligius, rescued from the California sound stage where it graced the set of his 1980s hospital drama "St. Elsewhere."

He has the case assignment board from "Homicide: Life on the Street," transferred from the Baltimore squad room it dominated during that series' 1990s run.

And smack-dab on his right shoulder is the emblem for "Oz," Fontana's prison drama that begins its fifth season on HBO Sunday at 9 p.m. CST. Permanently inscribed in his flesh, this is the "Oz" tattoo you see someone getting in the series' opening titles. Ouch!

"Someone had to get it," said Fontana, recalling with a laugh that, while the camera rolled, he not only got it once, but submitted to the needle's repeated retracings.

C'mon, just one more take!

Finally, the tattoo artist called a halt to the filming: "I can't let this guy bleed anymore."

Even so, that's standard operating procedure for Fontana. After 20 years, the Buffalo-born playwright-turned-TV-auteur bleeds onto the page starting every morning at 5.

Fontana writes every word of "Oz," where the prison population (along with viewers) will now have to adjust to the absence of Simon Adebisi, the hulk in the stocking cap who ran the prison's drug trade. He was offed by another con in last season's finale.

But replacing him in the constant churn of characters (the "Oz" Web site is an invaluable who's who) will be several new faces. One of them is disgraced TV evangelist Jeremiah Cloutier, who soon takes up residence at Oswald penitentiary.

He is played by none other than "Beverly Hills 90210" alumnus Luke Perry.

Even for a series with a large and diverse ensemble (including Ernie Hudson, Terry Kinney, B.D. Wong, Dean Winters, J.K. Simmons and Eamonn Walker), a former teen heartthrob stands out.

"We thought we'd take advantage of the fact that he's famous," said Fontana, describing Perry as an old friend. "He plays a televangelist who is famous to the characters on the show."

Perry showed up for filming with long hair and a beard which he offered to snip. "I took a look at him," said Fontana, "and he looked like Jesus Christ." Great! "I didn't want a Jimmy Swaggart clone."

This charismatic Christian thus becomes the latest spiritual leader to join the jailhouse populace � and to unsettle other inmates. Just as in the larger world, faith in a cellblock can bring comfort, but a clash of doctrines can ignite a firestorm.

That suits Fontana fine. He writes not only to tell a dramatic tale, but also to explore things that intrigue and even plague him. Spiritual issues are high on his list.

"But the politics of religion don't interest me at all," said Fontana, who was raised a Catholic. He pointed to the staff psychologist, Sister Peter Marie (played by Rita Moreno). "How she acts in the course of dealing with the men in the prison comes out of her own spirituality, which is influenced heavily by the Catholic Church � but not exclusive to it."

Be warned. Some viewers may find these holy explorations overshadowed by the more shocking elements of "Oz."

But Fontana feels it's all of a piece: a tight, troubled universe of people trying to get by.

"I've always been happy that HBO never promoted the show as anything other than a drama series," said Fontana. "For me, 'Oz' is not about frontal nudity, it's not about raw language, it's not about violent behavior. And that's not what I want people to come looking for. I want them to watch because they're involved in the characters."

MORE: www.hbo.com/oz