Finals Week continues on MasterChef 2015. Over the past six weeks, the country's most promising amateur cooks have been whittled down to the best four. All of them have just one goal: to lift the coveted MasterChef Champion trophy. Tonight the final four become three. First, the four talented amateur cooks embark on a culinary odyssey to Sweden, where they will face a series of challenges they will remember for the rest of their lives. Here a whole new culinary movement is taking hold. Young, ingenious chefs are gaining global attention by bucking the trend of a scientific approach to food and returning to thousand-year-old cooking techniques. Over the 48 hours the finalists will experience two very different restaurants leading this revolution. The first has no menu and invents dishes on the day with whatever ingredients their suppliers bring in. The second cooks with no electricity or gas and puts its faith in the most primitive cooking method of all - open fire. Tonight, these amateurs are about to experience a baptism of fire as they return to the cookery techniques of the culinary Stone Age. Out of their comfort zone, the final four are in a world like no other where every ounce of passion, understanding and character must be used to see them through. With their Swedish adventure over and the MasterChef final just two days away, they return to London to fight for their place in the competition. Tonight's final challenge is to cook an exceptional fish dish for John, Gregg and a guest judge, two-Michelin-starred Nathan Outlaw, renowned for his expertise with fish and seafood. Only three can go through to the penultimate and final MasterChef challenges, so the pressure is on to keep their dream of winning the competition alive.