Sgrìobag is a monster who lives in a plain white world, but with the help of her pencils and paper it does not stay white for long. Sgrìobag uses a straight line to a draw a whistling pig called Murchadh. He is very happy in his straw house once Sgrìobag has drawn him a bed to sleep in, but then a big wolf turns up and blows his house down. So Sgrìobag draws Murchadh a new house, this time made of bricks. But the wolf was not trying to blow his house down - he was trying to whistle like Murchadh.