Nicole Kidman on her new film Before I go to Sleep

Before I Go to Sleep, the first novel by Steve J Watson, became a Sunday Times and New York Times bestseller after it was published in 2011.

It has now been turned into a thriller starring Nicole Kidman and British actor Colin Firth.

Nicole Kidman told Brenda Emmanus why she wanted to play the role of Chrissie, a woman with amnesia who uses a daily journal to piece together her life.