Noel Fielding and Sandi Toksvig invite four more celebrities into the tent to expose their soggy bottoms. Taking part are musical comedian Tim Minchin, leader of the Scottish Conservative party Ruth Davidson, Made in Chelsea star Jamie Laing, and singer Ella Eyre. There's no time to loaf around with their signature challenge. Prue's got a fancy technical up her sleeve. And the showstopper stakes are high as the bakers build meringue towers. Judged by Prue Leith and Paul Hollywood, the celebs will have to pull out all the stops to be crowned star baker, and to encourage viewers to raise money for Stand Up To Cancer.