"Every night, in the middle of the night, Nick and his friend Peter dig for treasure in the school oval. The oval is built on an old rubbish heap and in the rubbish are old bottles which Nick and Peter sell to a second-hand dealer for good money. They are on a quest for the best and most valuable bottle of them all - a cobalt blue torpedo bottle. Then they are sprung - by Nick's sister Lisa, then their parents, who, when they discover all the money, can't believe it is just from selling bottles. Then just as they have almost talked their way out of it, the police arrive, and it looks like their treasure-hunting days are over for good..."--Provided by publisher.