Subterranean Blues. Of course, the campground compost heap is extremely tempting to the goblins. Because if they could get their paws on everything that people throw away, they would have a richly filled food basket for a long time. But between desire and reality pushes yellow hair, Mia's dad. He does everything to keep the rubbish heap free from those who turn it upside down every night. Not only does he neatly surround it with chicken wire; as a special highlight, he also installs a camera that is supposed to show him who is approaching the waste illegally. From now on the goblins have a problem! Can they trick the camera? Can they slip under the wire mesh? Or can't they perhaps enlist the help of those they really don't like at all: the moles. Because their tunnel is perhaps the best way to find a way to the compost heap unseen and without making a sound!