Joe and Shereen welcome Race Across the World winners Alfie and Owen to the studio alongside stars from Strictly Come Dancing - but who will be slimed? Joe and Shereen go head-to-head in their first challenge of the series, and there is another game of Back to the Drawing Board. Plus cartoon fun in Grizzy and Boy Girl Dog Cat Mouse Cheese.

Alexandra Chave - aka Piper in The Next Step - struts into the Mash-Up studio. Online star ThatsWatson takes on the Mash Car Rally, and there is a high-octane Joe v Shereen challenge. Plus cartoon fun in Pokemon, and somebody will be slimed!