A celebration of children's books presented by David Walliams, who counts down all the way from 50 to one. The show features guest appearances from Miranda Hart, Rob Brydon, Sarah Hadland, Meera Syal, Rufus Hound, Grace Dent and Levison Wood - who re-live their childhood experiences. David visits Paddington station with Michael Bond, takes tea with Judith Kerr, and visits Sir Quentin Blake's studio while he brings to life some of Roald Dahl's classics. Julia Donaldson, Michael Morpurgo, Lauren Childs, Michael Rosen and Dame Jacqueline Wilson all bring their work to life in conversation. And as an extra treat, Julie Walters and Martin Freeman read extracts from the top 50, including Treasure Island, Just William and The Hobbit.