Che Chesterman, Lauren Murray, Louisa Johnson, and Reggie & Bollie return to the stage as Caroline and Olly present the results of the weekend's viewers' vote. Only three of the semi-finalists will be able to progress to next week's final, meaning one unlucky act will face bowing out of the contest ahead of the climax. Tonight's show also features a group performance, as well as a performance by Sia. (thetvdb.com)