Keeley Hawes never watches drama series.
The 40-year-old actress can next be seen in the second season of 'The Missing' but she never watched the 2014 run of the show as she prefers relaxing with a documentary as she feels too close to fictional sagas because of her own work.
She said: "I must admit I hadn't seen [the first series] - watching drama is a busman's holiday for me.
"You've usually already read the script or you know everyone in it.
"I tend to watch more documentaries. But once I was sent the script, it was one of those things that I just couldn't stop reading, like 'Line of Duty'. "
Keeley admitted the heavy subject matter of 'The Missing' - in which she and her on-screen husband, who is played by David Morrissey, are reunited with their daughter after 11 years - took its toll, especially after her most recent work in 'The Durrells'.
She said: "I came in thinking I was going to be like the cheerful Mrs. Durrell off-set.
"You have to be positive when you're working on something like this, but it's hard.
"It's one of those jobs where the scenes are long, relentless and upsetting. We've just been filming funerals and cemeteries."
The 'Line of Duty' actress was pleased to reunite with David on the show, after they previously worked together on 'Our Mutual Friend' in the late 1990s.
She told Closer magazine: "I've loved working with David Morrissey and the actors playing our children.
"David and I worked together on 'Our Mutual Friend' - we were both so little then.
"David is hilarious, I don't think he's done enough comedy over the years."