Billy Grimshaw Jones is almost looking forward to having a new baby in the family – especially as that means they're moving to a bigger house.But then his mum loses her job. Disaster! Money will be tight and they'll have to cut back. So Billy does what Billy always does: he makes a plan.With the aid of little brother Stan and best friend Big Lauren, Billy sets out to make his fortune. Nothing seems to work, until Billy stumbles across an envelope full of twenty-pound notes . . .