The narrator kept his younger brother behind him because

  It was a Sunday afternoon that I saw the lorry standing in front of the post office. I had seen it long before my brother saw it, but it was he who said to me “Don’t you think it odd that the post office should be open this afternoon? What do you think is happening? ‘Come round the corner, out of sight, and let’s watch’, I answered. My brother Michael was younger than me, so I kept him behind me, and peering round the corner told him what I saw. ‘There are four men coming out, carrying a very heavy box’ ‘Oh! I exclaimed. ‘It’s a safe, ‘I think they’re burglars, said my brother who was full of suspicion. ‘One of them has fallen over ‘I said; ‘the safe is too heavy for them’. You go and fetch the police said my brother, ‘and I’ll stay here and watch,’ ‘No you go and get them’, I replied, because I wanted to see what was going to happen. My brother ran off and then, suddenly, a man came running out of the post office, shouting, ‘Hurry! Hurry! Get it on the lorry!’ He joined the first four and they managed to get the safe up on to the back of the lorry. When they had done this, the man who had shouted got into the driver’s seat, but the lorry would not start. Just then my brother came back with three policemen. To cut a long story short, the men were all arrested and my brother and I had to go and give evidence before a magistrate. The men went to prison, of course, in the end, but you should have seen the face of the leader – it was contorted with rage – when he learned that the safe they had managed to steal was empty, and all the money was in the bank.