As Ridley Scott's science fiction extravaganza, Blade Runner is re-released, Matthew Sweet is joined by the critics Roger Luckhurst and Sarah Churchwell, and by the philosopher Max de Gaynesford, to discuss its enduring significance. And Matthew talks to Eric Jarosinski, a writer who claims he found his creative voice on twitter under the name @NeinQuarterly, and to linguist and medievalist Kate Wiles, and book historian Sjoerd Levelt, about the parallels between the tweets of today and the marginalia of Medieval readers.