'One night a few years ago our neighbour Lisa knocks on our door. Her two young daughters are with her and I can tell something is up. The oldest, Sally, has just started primary school and the youngest, Patty, is a couple of years behind. We normally talk every day – mostly it’s the girls chatting away to me while I work out the front – but I haven’t seen them around much over the last few weeks. I’ve been worried about them and we are all happy to see each other.' (Introduction)