12 Most Shocking Betrayals In TV History

2. Nina Myers - 24

Espionage shows have a higher than normal chance of featuring some big time double crossing. It's in their genes. But 24 was on a whole other level, taking Jack Bauer's closest and most trusted ally and former lover and revealing her to be a mole. Nina was so completely trusted and unquestionably solid that the turn was inconceivable and devastatingly effective.

Towards the end of the first season we learned that Nina is the second mole at the CTU, having killed fellow rat Jamey Farrell and staged her suicide. In a moment, the known truth that Nina was always going to be there for Jack was flipped irretrievably on its axis and to make matters worse, she killed his wife after being told to tie up any loose ends.

She was far from the only mole - to the point that you have to wonder about the CTU's recruitment process - but hers was by far the most devastating betrayal.