As Doctor Who charity sketches go, this one was very special. The worlds of Classic and NuWho collided in a way that had never been seen before when Peter Davison returned to our screens as the Fifth Doctor for a multi-Doctor adventure that defied the realms of time and space itself. Written by Steven Moffat, the Tenth Doctor came face to face with his predecessor in this exclusive scene which aired to critical and fan acclaim during the BBC's Children in Need appeal night back in 2007.