It's Finals Week and five celebrities are within touching distance of the trophy. But to make it to the top, they will need determination, bravery and some outstanding cookery. The first brief of the week is to cook a dish inspired by a well-known chef. Can these cooks put their own stamp on creations that represent their chosen culinary genius? Judges John Torode and Gregg Wallace are hopefully in for a treat, as amongst the chefs chosen to spark the celebrities' culinary flair are Yotam Ottolenghi, James Martin and Heston Blumenthal. After scrutinising their creations, the judges will pick their favourites, leaving one celebrity to face the chop. The four who are left have no time to celebrate, as they have a train to catch in one of the most exciting challenges yet. They are taking charge of lunch service aboard the iconic British Pullman train, which paved the way for luxury travel in the 1920s. It has since been restored to its original grandeur and offers exquisite dining experiences. Head chef John Freeman has designed today's menu for the 20 passengers on board, and each celebrity will oversee one course. They must strive to stay on track, as all prep needs to be completed before the train sets off. Assuming they all make it on board, their next obstacle will be service itself, as the celebrities will be cooking and plating their dishes in compact galley kitchens. High-end food at high speed — this is a train ride they will never forget.