In opposite corners of the TV world, Sharon Small is sort of famous now. There are:

• Murder mysteries, calm and quiet. Small has done at least 23 "Inspector Lynley Mysteries" on PBS as Sgt. Barbara Havers, a time-saving role: "I was in the make-up chair for a minute, at the most," she said.

• Prime-time soaps, full of shell-shock surprises. Her "Mistresses" is now on BBC America (Fridays at 3, 6 and 8 p.m.), after making an impact in England.

"It really caught the public's imagination," Small said. "It became a water-cooler show."

There's been a lot to talk about over water coolers. The show's characters keep sinking deeper into trouble.

Katie (Sarah Parish), a doctor, has had affairs with a dying patient and then with his son. Siobhan (Orla Brady), a lawyer, is pregnant, but probably not by her husband. Jessica (Shelley Conn), an event-planner, was enjoying a lustfully heterosexual life, until she had her first lesbian affair and fell in love.

During this time, their friend Trudi (Small) has been the stable one. She has just received a $2 million check, as a widow of the World Trade Center attacks. Reluctantly accepting the fact that her husband Paul is really dead, she's moving on; she's also adjusting to the fact that an American woman says she had an affair and a child with Paul.

By "Mistresses" standards, Trudi's life is sort of mild. In an episode airing Friday (and rerunning a week later) that changes sharply.

In sheer plot details, this might seem like other prime-time soaps, from "Dynasty" to the British "Footballers' Wives." In execution, however, "Mistresses" is surprisingly calm and subtle.

"It needed to feel truthful ... and grounded," said SJ Clarkson, the woman who co-created "Mistresses" and directed some episodes. "I've actually directed 'Footballers' Wives'; I knew I didn't want it to be like that."

To make it more realistic, Clarkson pulled the four stars together for a bonding session. She "got us into a room and made us tell secrets about each other," Brady said.

This was serious stuff, Conn said. "It was like therapy."

These actresses offer a snapshot of the British Empire. Small is from Scotland, Brady from Irelad. Conn and Parish are from England, but Conn has family roots in India. Also, Anna Torv is from Australia; now a U.S. star in "Fringe," Torv plays Conn's love interest, Alex.

Being from Glasgow may make it easier to access emotions, Small said. "We're a bit more visceral, more on the surface. We have an emotional response to being a small country."

She grew up as the eldest of five children and went to school at Kiraldy College and the Mountview Academy of Theater Arts. After starting in Scottish and English TV, she drew U.S. attention as:

• Hugh Grant's former girlfriend in the movie "About a Boy."

• Havers, the no-nonsense, no-makeup cop from a working-class background, working with the upper-crust Lynley. "Her self-esteem was low," she said. "I enjoyed exploring that."

Playing Trudi, she's again understated. "As a working mom, she didn't have time to be glammed up all the time," Clarkson said. "She did sort of go to the school with her hair scarfed and scruffy old clothes."

Trudi was trying to live her life quietly, without drama. Now that becomes impossible.