This is one of the lesser known Ealing comedies and it has something of the Children's Film Foundation output to it too, as the youngsters cotton on to a dastardly plan to use the narrative bubbles in a children's comic to convey messages that unwittingly to the publisher and animator facilitate daring robberies. It's only when the young "Joe" (Harry Fowler) and his mates start to put two and two together, and with…