DI Alex Drake

When DCI Gene Hunt comes to her aid, she realises where she is and who she's with, having studied the case notes of Gene's former sidekick Sam Tyler.

As Alex works with narrow-minded Gene and his cronies to crack some tough cases, she makes it clear that she has her own way of doing things - although she can always rely on Gene to try and put her in her place.

While Alex slowly begins to enjoy her new life in the 80s, she's desperate to find ways to get back to the future and be with her daughter.

Born in London and a pupil at Sylvia Young Theatre School, Keeley is arguably best known for her role as Zoe Reynolds in BBC1's hit spy drama Spooks. She has also appeared in adaptations of Wives And Daughters and Our Mutual Friend, and in such films as A Cock And Bull Story, starring alongside Steve Coogan.

In 1999, Keeley played a young Diana Dors in the biopic Blonde Bombshell and, in 2002, she caused a stir when she starred with Rachel Stirling in BBC2's risque adaptation of Sarah Waters' novel, Tipping The Velvet.

Keeley, 31, has three children: a son Myles with her first husband Spencer McCallum, and Maggie and Ralph with her Spooks co-star Matthew Macfadyen, whom she married in 2004.