Rhea Seehorn gets away with it

“The problem is that Kim’s ideals aren’t wrong,” she said. “But the way she does it is.”

In five and a half seasons, Kim’s long slide to perdition has become undoubtedly the narrative keystone of the series. It has not always been so. When it started, “Saul,” a prequel to “Breaking Bad,” seemed mostly focused on transforming slippery but fundamentally decent Jimmy McGill (Bob Odenkirk) into Albuquerque’s sleaziest lawyer, Saul Goodman. Kim’s ultimate role was then uncertain, even for the screenwriters.

“We had no idea when we started how important his character was going to be,” said showrunner and co-creator Peter Gould. “If you watch the pilot of the show, she probably has three lines of dialogue.”

It soon became clear, however, that the character of Seehorn, who started (outwardly) as a straight arrow with a promising legal career, would be an integral part of Jimmy’s makeover. Like Jimmy, Kim was breaking badly. Unlike Jimmy, however, Kim never appears in “Breaking Bad,” leading many fans to assume the worst. The stakes were always potentially higher for her than for the guy with her name in the title.

That seems like a lot to bear, given that “Saul” is one of TV’s most critically acclaimed series. But if so, Seehorn, 50, who has been performing on screens and on stages since the ’90s, handles it with grace. Unlike the purse-lipped, inscrutable Kim, Seehorn isn’t afraid to be vulnerable, either professionally or, ultimately, in conversation. She has no problem, for example, talking at length about a rash. She’s funny and has a blinding, spontaneous smile that made me wonder if I’d ever seen Kim Wexler’s teeth (despite all those teeth-brushing scenes).