Cult Spy Icon: Gretchen ('Prison Break')

Totally shattering the notion that the realm of Prison Break is ruled by pure testosterone, the ruthless Gretchen Morgan entered the fray in the show's third season and instantly had everyone by the cahones.

Susan, as The Company's vicious operative was originally known, was a breath of fresh air during a lacklustre third season. For every sweat patch mustered by the brothers bland - Scofield and Burrows - would be more than matched by the scowls of disgust that dominated her visage. When she threatened to have Sucre's beloved Maricruz cut to little bits, you instantly believed her. When she put a knife to the throat of LJ, you knew she would happily decapitate the simpering simpleton with all the emotion of filing her nails, although a timely phone call from Burrows intervened on that occasion.

She established her killer credentials primarily through the beheading of Scofield's beloved Sara Tancredi, proving that both bark and bite were in harmony (and that she had clearly watched Se7en far too many times). Other memorable moments that proved her steely demeanour included her valiant attempts to defy 'water torture' in Sona and the subsequent slaying of the new, sympathetic prison boss.

However, there was more to Gretchen than mere plot function. Much needed depth was given to her character through a series of flashbacks that depicted her own suffering at the hands of torturers, plus cryptic hints that she believes she is actually doing the 'right thing' and is not a mere mercenary. In addition, largely thanks to the superb performance by Jodi Lyn O'Keefe, Gretchen manages to exude a strong sense of femininity throughout. Very much in the femme fatale mould, she'll happily seduce a man then leave him for dead once she's accomplished her goal.

Here's hoping that Gretchen is back for a proper showdown with Scofield should Prison Break return to our screens. No tattoos will save him from her mighty wrath!