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David Walliams, Dannii Minogue, David Tennant and Marc Almond plays live.
Joining Chris is toastologist Dr Dom Lane and Carp Wars fisher Ian "Chilly" Chillcott.
Have Chris and Dr Michael Mosley survived sugar-free February?
Ben Fogle talks about campervans and Terry Deary on Horrible Histories.
Chris speaks to John Cleese live from California and meets Jarl, a real-life Viking.
Sara announces her Sound of the 80s Danceathon for Comic Relief.
Sara tells you how you can be at this year's 500 Words final at the Tower of London.
Sara finds out how Morph is celebrating his 40th birthday from creator Peter Lord.
Sara (in for Chris) finds out what it's really like to be a florist on Valentine's Day.
Sara Cox is joined by children's author and 500 Words judge Frank Cottrell-Boyce.