A gang of kids called the "Wormsley Common Gang", after being convinced by a
Trevor (T.) is the gang member who gets the idea of destroying the old man's house. He is not a normal person and you can perceive this by the way he acts and thinks, but this is an obvious way to behave, after surviving a war.
The old man, Mr. Thomas (or as the gang call him, "Old Misery") is a just a good man, who treats everyone politely and doesn't harm anybody, but despite his kind acts, he is about to experience something h doesn't deserve.
Its supposed to be a fun story, involving 'black humour', but personally I don't find it funny because what they want to do, is something inhuman and terrible, besides I wouldn't like that it occurred to me. It's an interesting story though, where you can experience different feelings such as suspense. You can also perceive the ways of how people behaved/thought after harsh situations, like surviving a war in this case.