Mr and Mrs Li aren't quite sure what to make of the strange beings that crash into their house at midnight.

Their eyes are very big, their skin is very blue, and their shape is very hard to describe. And even though they insist that they are DEFINITELY human, they're not like any human Mr and Mrs Li have ever seen.

Fortunately the Lis are both very kind humans, so when the visitors ask for help, they don't think twice before giving it.