The four remaining teams of professional pastry chefs must master petit gateau, creating 36 identical petite charlottes and 36 shaped macarons in just two hours. For their final challenge, the teams must put an innovative spin on the classic towering French celebration cake, the croquembouche. Who can reach new heights and create a skyscraping choux bun showpiece in just four hours and who will face a dramatic fall from grace and the disappointment of leaving the competition?