A place in the quarter-final is at stake this week, and the challenges are all about lingerie. Host Sara Pascoe starts the sewers off with a fiddly pattern for a lace underwired bra and matching knicker set. With such small pattern pieces, there is no margin for error, and Patrick and Esme's eagle eyes will spot every mistake. The Transformation Challenge requires the sewers to take thermal underwear and turn it into daywear.