I picked up some rocks at my parents' house, intending to paint them in the coming weeks and months. I was examining one, planning out what I might do with it. I was thinking it might be a hedgehog. Then someone suggested that the shape resembled the face in Edvard Munch's The Scream. It only followed, then, that the stone might also be the Silence from Doctor Who. That idea really took hold. Luckily, I had a fine tip permanent marker in my bag.