Dr Who, the time travelling superhero, has sent a personal message to a boy from Southampton who has lost his Grandma. And the video has now become a worldwide phenomenon. Nine year old Thomas Goodall was struggling to cope after his Nan's death. So he wrote to actor Peter Capaldi. A few days later Dr Who sent him a video message - which has already been watched over 750 thousand times. And it has had a massive impact on young Thomas. Andrew Pate has more.