Calling All Boys was one of my most favourite books. It combined a pretty good story of a group of Pommie schoolboys thwarting a gang of thieves with an exploration of the methods police used to solve the crimes. Remarkably obliging policemen allowed the boys to peer over their shoulders and see how fingerprints and other clues were processed, and participate in the search for evidence. It all seemed so very modern and exciting at the time, especially because the criminals seemed rather dangerous for the the kind that usually turned up in children’s crime fiction.
As such, it was some sort of forerunner of the doco drama, with a touch of Disneyland about it, while never leaving the realm of the Great Enid. It was the sort of stuff to make any boy want to be a policeman when he grew up.
A good disguise. In case you don't realise it, all of these people are Alec Guinness