George is scared of everything, so scared all the time that his plea for someone to save him from the monsters reaches the Doctor in the TARDIS, far away in space and time.
It’s so unusual the Doctor can’t ignore it. Nobody, especially not a child, should be afraid all the time, and he’ll do whatever he can to help.
But George is no ordinary child, he’s not human, he’s an alien cuckoo in the nest, and he’s scared that his parents don’t want him. Once the Doctor understands, the problem is easily fixed. All it takes is unconditional love.