On a trip to the safari park, Harry and his dinosaurs are horrified to discover that some animals are in danger of becoming extinct. Harry wants to help save them but Sam says he’s too small and won’t be able to do anything that will make a difference. But Harry is desperate to do something and gets to work making some posters for the window. He takes them off to a local shop who won’t put them up because they’re too small to be seen – but when Harry goes back the week after, his posters have been made into cards and are selling like hot cakes! He quickly discovers that it doesn’t matter how small you are – you can be a tiny as a tick on a turtle’s tail and still make a big difference!