The contestants finally discover they are not alone - this is a race, and only member of the team that reaches the island first is in with a shot at the £200,000 prize. With both groups way behind schedule, will this new information spur them on? Meanwhile, moles David and Alex return to dish the dirt, and two members of each team face a dilemma - do they take 10 anchors back to the build or secretly pocket £10,000?