begins on BBC One on Thursday at 9 pm for its 20th anniversary series and the opening episode finds delving into her roots to uncover the truth behind two harrowing family stories. But the and star admits that she was rather wary about what she might find out when she signed up for the genealogy show. "I don't like the unknown, so I was like, 'What have I done?’," shares the Nottingham-born actor.

"You don’t know what anyone’s going to tell you." Here, we look at the discoveries Vicky McClure made in A difficult upbringing Vicky was always close to her beloved late paternal grandmother, "Nonna Jean", and she headed to Jean's birthplace in Grimsby, Lincolnshire as she was keen to find out why Jean was given up as a baby and raised by foster parents who were cruel to her. “I knew that Nonna Jean was taken in by awful people that treated her badly, it was horrendous,” says Vicky.

“But we’d never got to the bottom of why she was abandoned and the story behind it. I was hoping they [her birth family] had a good reason not to keep her.” Vicky discovered that her great-grandmother Ruby, known as Winnie, already had three older children when she gave birth to Jean in 1925, and that Ruby’s husband, Thomas Compton, a ship’s steward, was not Jean’s father.

Get the What to Watch Newsletter The latest updates, reviews and unmissable series to watch and more! “Thomas maybe couldn’t bring up a child that wasn't his. And they didn’t have space. So the most reasona.