​​​​​​I wrote this book in South Africa way back in the seventies, so it will be quite different from today's school stories written in the USA. It is also dated as to writing style. Nevertheless, the story is enjoyable.
The new girl at Penvale Primary School proves unpopular. So is a strict new teacher who is quite unlike their absent-minded old teacher. To top it all, there is a grumpy man who lives in the street where the gang of schoolchildren love to do some downhill roller skating. 
The children make plans to deal with all these problems, but discover something going on in the neighborhood far bigger than any of these annoyances.