Linda Wallem thought she had found a sister. As a leader at the University of Minnesota's Alpha Phi sorority in 1982, it was her job to recruit new members. After a few minutes of interviewing Liz Brixius, she knew she wanted the freshman in her chapter. Instead, Brixius chose the house next door.

"I would see her throughout the year and think, 'Oh, there's that nice girl who went to that bitchy sorority,'" Wallem said.

The two women didn't chat again until 20 years later, when they were reintroduced at a Los Angeles party. This time the friendship not only stuck, but led to a professional partnership that produced "Nurse Jackie," which returns Monday for its second season. Emmy winner Edie Falco may play the title character -- a drug-snorting, rule-breaking, unfaithful caregiver -- but it's Wallem and Brixius who create the story arcs, run the writers room and supervise everyone from the caterers to the camera operators.

"They're probably the hardest workers I've seen in my career," said seasoned actor Peter Facinelli, who plays a self-absorbed doctor who becomes the poster boy for the financially ailing hospital. "They're sitting behind the monitor and writing at the same time. Every time I finish a take, I always look over to them and I can tell if it went well because they'll have big smiles on their faces."

Both women say their time in Minnesota was crucial to their success -- but for very different reasons.

Dudley Riggs and rehab

Wallem grew up in Rockford, Ill., but fell in love with Minneapolis when a junior-high instructor took several students to a Guthrie production of "The Matchmaker."

"We thought we were in heaven," she said. (Also in that cramped station wagon: Joe Mantello, who would go on to appear in the original cast of "Angels in America" and direct "Wicked.")

Wallem, determined to become a comic actress, majored in theater at the U and eventually got cast in the school's Centennial Showboat melodramas. But Wallem quit school and the Showboat when she got hired by Dudley Riggs' Brave New Workshop, a break that upped her game.

"The best thing I ever did was learn improv," said Wallem, a fast-talking, gregarious spirit who could probably still slay a crowd at a comedy club. "You're forced to open your mind, open yourself to possibilities. I credit Brave New Workshop with everything."

Still hoping to establish a stage career, Wallem teamed up with Riggs regular Peter Tolan in hopes of becoming the Nichols-May of the '80s. They performed cabaret-type shows in Boston and New York for six years.

Tolan would go on to pen such box-office hits as "Analyze This" and "America's Sweethearts," and co-create the FX series "Rescue Me." Wallem would also shift behind the scenes, writing and producing for "Cybill" and "That '70s Show."

But she didn't really find her groove until she got reacquainted with Brixius, who came to Los Angeles via a rockier path.

The Excelsior native was in her freshman year at the University of Minnesota when her sorority sisters staged an intervention. By the time she turned 20, she had gone through four rehabs.

"My fifth one would have been free," said Brixius, a statuesque chain-smoker with a sharp, salty tongue. "Alcohol was a gateway to everything. My family drank a lot and could handle it, but when I drink I turn into something else. I'm in your handbag like that."

After getting sober, Brixius finished her education at St. Kate's, studying poetry. She used her talents to teach and write in Massachusetts. After a few years, she decided to try to get into the world of soap operas, and while she fell short of that aspiration, she did sell a screenplay to Sandra Bullock's company. The film was never made, but it introduced her to the Hollywood community -- and got her an invite to that cocktail party.

Nurse's aid

Edie Falco, hot off the success of "The Sopranos," was looking for a new challenge when she came across a script for a series about a complicated nurse in a big-city hospital. She didn't like it. The story was too supernatural -- doctors hung like bats in the janitorial closet at the end of their shift -- and it didn't play to her ability to play earthy characters.

Showtime president Bob Greenblatt convinced Falco to take another look after he asked someone else to take a crack at the pilot. He called on Brixius and Wallem, who had previously supervised a pilot called "Insatiable," about Midwesterners struggling with addiction (Wallem went through rehab herself in her 30s). The show went nowhere, but Greenblatt was impressed by the new team.

Brixius said they had a huge advantage in their rewrite because they had Falco in mind.

"She's built up such goodwill over the years that we knew people were probably going to forgive her if she stole drugs from a patient or broke her own finger," she said. "You can give her anything and she's going to find the truth."

Falco and her production partner, Richie Jackson, liked the new script. More important, they liked Brixius and Wallem.

"I remember that we met the day after Halloween, and Edie and I were talking about taking our kids trick-or-treating, and that's all they wanted to talk about," Jackson said. "That's when we knew that these were people we could be comfortable with, that believed in the same things we do."

That ability to get along is crucial to "Nurse Jackie" because of the breakneck speed of the work schedule. The crew shoots 12 episodes in 12 straight weeks. Through it all, the would-have-been sorority sisters have strengthened their relationship.

"I would never, ever try to dissect it," Brixius said. "Things that come out of my brain, people might think are coming out of hers, and vice versa. It's not that she's the funny one and I'm the serious one. It's just in the air." • 612-673-7431