It's Tribal Challenge Week in the Shipwrecked competition, and in a massive shipwrecked shocker there are five new arrivals for the Tigers and Sharks to woo. In preparation for the new arrivals on Shark Island, the tribe have made a series of special seats for each of them, which they use for a round of getting-to-know-you 'speed dating'. The next day the flag goes up and both islands must compete in a dynamo challenge, where each team must pedal for a set amount of time to see who can generate the most energy. The winning tribe will win a crucial third night with the new arrivals, who will choose a tribe, and be the deciding factor in who wins the overall competition.