An episode devoted to the internet's 50 greatest video mash-ups. It's a global phenomenon born and raised on the internet and the rules of the game are simple. Take something cherished and loved, chop it up, change it, move bits around, add things, even replace the audio with the sound of a pig playing the kazoo - do what you like, as long as you make it funnier. From the brilliantly stupid Darth Vader playing the blues, Professor Brian Cox talking through the Wonders of the Stoner System, a sneak preview of Predator - The Musical, and not forgetting the very naughty Delicious Ms Dahl, only the best mash ups make this countdown. And, with exclusive interviews with some of the creative - or crazy - brains behind them, viewers get a glimpse at what inspired these brilliant videos. Expect nostalgia and hilarity aplenty as our favourite movie scenes, famous faces, TV moments and internet classics get the Mashed 'n' Mixed treatment, all in the name of online entertainment.