It's the Blue Peter Children in Need special! To celebrate the fundraising extravaganza, the team link up with Radzi at Elstree as he prepares to sing the official 2014 Children in Need single with Gareth Malone's All Star Choir. And find out if he manages to scale the final part of his epic Children in Need challenge - climbing the world's highest artificial climbing wall in Switzerland! Also, the Royal Marines drop in with an incredible stunt outside the Blue Peter studio.