Overview:The successful auditionees head to London's Hammersmith Apollo for the biggest bootcamp ever. Judges Simon Cowell, Dannii Minogue, Louis Walsh and Cheryl Cole will be putting 200 acts through their paces. Who will be able to handle the pressure and stand out from the crowd, and who will be heading home? After this first challenge, only 50 acts can go through to the next bootcamp stage. Host Dermot O'Leary is on hand to offer condolences to the unlucky and celebrate with the chosen few.