Fans of the Halo franchise are invited to help mark the upcoming release of Halo 4, by entering to take part in a once-in-a-lifetime experience at a secret location in Europe.

Only five people from the UK will be selected to take part in what Microsoft is calling the "ultimate adventure into the unknown." Those lucky enough to be selected will be transported to an undisclosed European location for a top secret assignment where the Halo universe will be brought to life like never before.

Information will be released via Xbox's social media channels over the coming weeks to hint at the twists and turns of the quest - use hashtag #halo4experience to follow the tweets.

To be in with a chance of attending, fans must complete the UNSC enlistment form at to qualify for evaluation. Applicants must be aged over 18, a resident of the UK and authorised to travel to an undisclosed location on October 30.

Halo 4 is released worldwide on November 6.