Joe Lycett hosts the semi-final, as the four remaining sewers go back in time to the 1940s. Attempting to revive both the glamorous and thrifty styles of the decade, they tackle the decade's most elegant and innovative garments. First up, judges Patrick Grant and Esme Young challenge the sewers to make the decade's most famous trousers, Oxford bags. For the Transformation Challenge, the sewers are set a wartime task to turn old parachutes into glamorous dresses. In the Made to Measure challenge, the sewers take on their final icon of 40s fashion, Dior's New Look. Characterised by an hourglass silhouette and involving masses of fabric, the sewers must exaggerate their model's figure to create the iconic shape.