A dazzling array of stars are standing by to play their part as this year's marathon fundraising event gets under way. Terry Wogan is joined by co-host Tess Daly to launch the extravaganza in aid of disadvantaged children, which begins with an excerpt from West End hit Charlie and the Chocolate Factory. There's a Doctor Who exclusive, plus the cast of Eastenders and their Albert Square homes are all transformed as part of a special musical treat.