Let’s put it this way. If you were starting a fantasy law firm for the USA drama Suits, your first pick wouldn’t be a lawyer.

It would be Donna Paulsen (Sarah Rafferty, top), who is nominally an executive assistant, but whose more accurate job description would be that she holds the joint together.

With Suits returning Wednesday at 10 p.m. ET for the final six episodes of its sixth season, that job has become a little tougher. 

Jessica Pearson (Gina Torres), managing partner in the show’s central law firm of Pearson Specter Litt, has left. Almost everyone else who worked there is also gone, after Mike Ross (Patrick J. Adams) admitted he’d been practicing law out of the firm without a license.

Now Harvey Specter (Gabriel Macht, left) and Lewis Litt (Rick Hoffman, left) have to put the pieces back together.

Fortunately, they have Donna.

“It’s challenging,” says Rafferty, and also complicated.

Harvey and Donna, who has worked for him for 12 years, are in some kind of love, though they don’t talk about it much. In the final episode last fall, Harvey and Donna stood alone and silently held hands.

“I loved that,” says Rafferty. “It showed that when painful moments happen, like Jessica quitting, Harvey and Donna reach for each other.”

An early scene Wednesday revives that notion again. But Harvey and Donna are not your standard will they/won’t they TV drama setup.

For starters, their other storylines feel more urgent and, frankly, more important.

“It’s there,” says Rafferty. “But it’s a slow burn. It lets us appreciate the mystery of the relationship – because neither of them is equipped to face what it really is between them.”

And where will it end up? Rafferty says darned if she knows.

“I’m really glad I don’t have to make that decision,” she says. “I think there are seeds in the next six episodes.

“We’ll see a little more of Donna talking about where her life might go and see more of who she is in addition to being part of Pearson Specter Litt.”

Rafferty notes that we already know part of where Donna has been.

“She wanted to be an actress,” Rafferty says. “Her family had money, but her father gambled it away and she finally gave up on acting because she was afraid she wouldn’t make it and she had the opportunity of following a path with more financial security.”

Since Rafferty herself majored in theater at Hamilton College, studied theater at Oxford and attended Yale Drama School, the actress’ backstory wasn’t hard to incorporate.

Except, of course, the part about feeling insecure because actors often don’t know if and where they will work again.  

“You mean being afraid every day?” says Rafferty with a laugh. “No, that would never happen.”

Donna’s backstory does help explain why she isn’t, say, a lawyer herself.

“She is very smart, sometimes the smartest person in the room,” says Rafferty. “But she has a different kind of intelligence than the other characters. Harvey is great with professional skills and not so great with emotional intelligence.

“Donna guides him through his emotional life, because he can’t do that on his own.”

Donna’s loyalty to Harvey, which includes protecting him, has led her to a couple of acts that startled viewers. Rafferty, too.  

“Quitting Harvey to go work for Lewis was huge,” says Rafferty. “I had a great conversation with [show creator] Aaron Korsh about that. Would she really do it? And we decided yes, she would. After a line was crossed with Harvey, she didn’t feel she could fulfill her job description in the same way.

“We ended up exploring her humanity.”

Things were less abstract when she found and concealed a document Harvey had told a judge didn’t exist, or when she impersonated a public official to get information in another case.

“She was doing what she thought had to be done,” says Rafferty. “She has a certain blindness. Because she’s almost always right about everything, when she’s wrong, things can go really wrong.

“She broke the law and she was too arrogant to think she could get caught, and maybe go to jail.”

These kinds of things happen on TV dramas, of course, and Rafferty says she didn’t know when she took the role how central Donna would become.  

While she had done numerous one-shot TV episodes, she had not had a regular role before Macht, an old friend, sent her the Suits pilot.

“I could hear each character’s voice,” says Rafferty. “They were all drawn so clearly. They’d set up this complex relationship [between Harvey and Donna], and you could tell from the way she spoke that she was quite a girl. I thought there was a chance for her to really grow.”

Six seasons later, that’s what happened, and Rafferty says she’s grateful. “I mean, six seasons,” she says. “I might never have an opportunity like this again.”

Suits will eventually end, of course, like all TV shows except The Simpsons, and the 44-year-old Rafferty, who has two young children, says she’d like to do “all kinds of things,” including comedy, “as long as I’m breathing.

“But when Donna is gone, I’m going to miss her.”