While Logan has been working since graduating from the Royal Scottish Academy of Music and Drama in 1977, she didn't score a massive hit until the BBC dramedy "Lovejoy" (1986-94), in which she played Lady Jane Felsham opposite Ian McShane's titular rogue antiquities dealer.
"I was upstairs at this point," said Logan, noting that, at its peak, "Lovejoy" attracted 18 million viewers.
Still, it would take some 25 years for Lady Felsham to lead to Mrs. Hughes. "We didn't offer the part to anyone else," said "Downton" executive producer Gareth Neame. "There's something about Phyllis' personality. She is that character. She is the person you go to when you have a crisis."
With both Lady Sybil and Downton heir Matthew whacked in season three, expect the new season to keep Mrs. Hughes busy when "Downton" debuts Sunday in the U.K., early January in the U.S.
The same cannot be said for the 57-year-old actress, who said global success of "Downton" has not translated into a blast of other job opportunities.
"It's very thin on the ground, decent roles," she said.
To return to the role of Mrs. Hughes, Logan again had to be transformed into a buttoned-up matron. "They did look older than they actually were in those days," Logan said, adding, "They had hard lives."
Perhaps that's all the more reason that Mrs. Hughes could use a little love.
"So many people like the idea of Mrs. Hughes and (butler) Mr. Carson getting it together," Logan replied. "It might spoil it a bit. But, I don't know. The jury's out of this one for me still."