The Top 8 Mystery Box Challenge had the eight previous Mystery Boxes return to the kitchen, with each of the contestants cooking with the ingredients of one of them. After the 60-minute cook, Matthew (with the Power Apron week box), Reynold (with Heston's history box) and Billie (with Poh's Asian-themed box) impressed the judges, and Billie won the advantage into the Invention Test. She chose earth (over wind and fire) as the conceptual theme of the 60-minute challenge. The judges told the contestants that there would only be a Top 4 in the Immunity Challenge and a Bottom 4 to elimination. Georgia, Reynold and Jessie received praise for their desserts, with Sara completing the top 4. Thus, Billie, Matthew, Jessica and Ashleigh were sent into the pressure test.