Minnie and Moo are good friends as well as being large and incredibly naive cows. The many stories written by Denys Cazet about the bovine duo manage to hit the elusive early reader target of being funny to both the children reading the story and the adults who are carefully coaching or patiently listening. Some of the humor comes just from being silly, some from misunderstanding key points about the world.
This particular installment leans towards the silly end of the spectrum. Minnie and Moo are relaxing in a hot tub with some cheese when aliens invade. The cows are totally oblivious to both the space ship and the aliens. Towards the end of the book it is revealed that the aliens – shown only in closeups up to that point – are actually quite small. When the friends manage to destroy a spaceship totally by accident, the aliens decide the inhabitants of the Earth are simply not worth the trouble, and leave. Simple, silly, and a lot of fun.