It's the quarter final, and the last four designers in the competition are in the village of Beer in Devon, taking on a cosy sitting room each in a row of coastal cottages. It'll be down to Sophie and Daniel – and guest judge interior and architectural designer Oliver Heath – to decide who has what it takes to go through to the final three. In their bid to become a semi-finalist, one designer shows skill with a hand painted mural, but has a disaster hanging wallpaper upside down on the opposite wall. Our second quarter finalist has a terrible start when they discover damaged, damp walls in their room, and things don't improve when the judges have grave concerns over the whole look of their New England scheme. The third designer attempts a modern look, but their design knowledge is called into question when they use wood effect wallpaper and cherubs alongside contemporary furniture. Meanwhile the last quarter finalist goes dramatically off-brief with dark navy walls and charcoal coloured furniture. Have they pushed their homeowner too far? As well as their schemes, they'll all take on a surprise challenge. They'll be asked to join forces with one of their competitors to test their teamwork skills. Each pair gets a trunk to upcycle, but working together with one of their rivals brings some strong differences of opinion. Architectural historian Tom Dyckhoff explores the coastal village, once known as a haven for smugglers, and uncovers its far reaching architectural influence. For the designers they have £1000, three days and the help of a small team to deliver a knockout scheme, and prove they deserve one of three places in the semi-final.