'Mrs. Wilson' Star Ruth Wilson on Sharing Her Family's Unbelievable True Story

John Russell
Q&A Steffan Hill/BBC Pictures

The only thing separating Ruth Wilson from the role of a lifetime: two generations. The Affair alum returns to TV to play her real-life grandmother in an unbelievable but true Masterpiece three-parter, Mrs. Wilson.

As Alison Wilson, she learns her husband, former MI6 spy Alec (Iain Glen), was secretly married to three other women. "It's a suburban housewife unraveling a mystery in the heart of her own life," the actress says, "and as she does that, her whole life unravels." Wilson opens up about family secrets — and about reprising her role as a murderess on BBC America's Luther.

How did you become aware of this aspect of your history?

Ruth Wilson: My grandmother gave us part of her memoir. She described meeting Alec and finding out on his deathbed about the existence of his first wife. It describes how she kept that secret from her sons.

Why did you want to play the role?

I felt it was the only way I could protect my grandmother. I don't mean making her likable; I mean that I wanted to be able to play her in all her complexity. I felt the denial, like, how could she not know something?

Did you draw on your memories?

I found it really hard to remember her properly. She died when I was 22, so I only knew her as the person at the end of her life, after she'd gone through this. From her memoirs and her poetry, I had to imagine the woman before.

How did your grandfather carry off this deception?

I think it's a combination of things. Working for MI6, he had to be undercover. He was creating aliases. We do partly think that perhaps wife No. 2 was a cover wife. [Alison was his third.] There's no definite written evidence from him. We don't know if these were wives for work or wives for play. [Laughs]

Your Definitive British Mystery Streaming List on Amazon Prime Video

Your Definitive British Mystery Streaming List on Amazon Prime Video

From 'Endeavor' to 'Crooked House' and beyond.

You're also going to be on the new season of Luther. What can you tell us about Alice's return?

I'm not sure what I'm allowed to say.… They thought she was dead. Well, she's not. There you go. When Alice is back, chaos ensues!

Mrs. Wilson, Premieres Sunday, March 31, 9/8c, PBS (check local listings at pbs.org)