Heat two of The Great Sport Relief Bake Off and four more well-known personalities throw their oven gloves into the ring for this charity special. Host Mel Giedroyc and judges Mary Berry and Paul Hollywood are joined by renowned choreographer and dancer Arlene Phillips, Radio Four's Fi Glover, The Apprentice runner-up and now presenter Saira Khan and art historian Gus Casely-Hayford.They face three classic Bake Off challenges, starting as usual with the signature bake, where their pastry skills are under the spotlight as they tackle tricky savoury flans. Novice Arlene is amazed when her pastry is described as 'lovely, buttery and short' but the pressure shows for one who ends up with the dreaded soggy bottom.Next is the Technical Challenge set by Mary Berry. Panic sets in and Mary is not impressed when it comes to judging her banana and chocolate chip loaves.Finally, it's the Showstopper Challenge and last chance to impress. The bakers are asked to produce a layered cake with the 'wow factor'. The mood changes in the Bake Off tent as the Sport Relief bakers attempt to redeem themselves in the eyes of the judges and step up a gear. Confident and experienced baker Fi impresses with homemade caramel rippled through her icing and Saira's plan to keep it simple and execute it well works as Mary called her sponge a 'perfect bake'.Who will sink and who will rise to win a place in the Great Sport Relief Bake Off final?