London: Actress Keira Knightley needed a break from all her 'dark' film roles so she signed up to star in a comedy 'Seeking a Friend for the End of the World'.

The 26-year-old  has done a series of dramatic roles since her breakthrough in the 'Pirates of the Caribbean' franchise, and  now she wanted to show off her playful side with a bit of light relief.

'I did do a comedy over the summer, because I thought, 'Jesus, this is just going from dark to darker to darkest, I need to lighten up a bit,'  Knightley said.

'I told a friend, 'don’t worry, it's much lighter,' and then when she asked me what it's about, I had to say, well, the end of the world! Maybe the apocalypse is as light as I can go right now,' she added.