The route to the live shows draws tantalisingly closer for the remaining X Factor contestants as they jet off to Judges' Houses in a bid to land a coveted place in the live shows.Offering a glimpse into the jet set lifestyle that The X Factor winner could have, the four categories travel to glamorous destinations across the world. With just one more chance to impress their mentor, each act will be hoping to convince them that they have the star quality required to reach the live shows.This year the Groups category will jet off to Ibiza to sing for Louis Walsh, Simon Cowell invites the Girls category to Malibu, the Overs category are hosted by Sharon Osbourne in her home in Los Angeles and the Boys category fly out to Nice to perform for Nicole Scherzinger.However, before they make their way to their destinations, each judge must nominate a Wildcard act for one of their fellow judges, choosing someone they feel missed out on a coveted place at Judges' Houses. The Girls Wildcard is nominated by Louis, the Overs Wildcard was nominated by Nicole, the Groups Wildcard was nominated by Sharon and Simon nominated the Boys Wildcard, making it 7 acts in each category and 28 in total.With crucial decisions to be made, each judge has help at hand from guest judges who know all about what it takes to have a hit record – Louis is joined by 2014 X Factor runner up Fleur East and Britain's Got Talent judge Alesha Dixon, Nicole enlists the help of renowned DJ Calvin Harris, Simon recruits former Spice Girls, Mel B and Emma Bunton and Sharon reunites with singer Robbie Williams.As ever, X Factor host Dermot O'Leary will be on hand to congratulate the lucky three, and console those that fall at the final hurdle.