A barn owl brought Neville a small package from his grandmother. He opened it excitedly and showed them a glass ball the size of a large marble, which seemed to be full of white smoke.
“It’s a Remembrall!” he explained. “Gran knows I forget things - this tells you if there’s something you’ve forgotten to do. Look, you hold it tight like this and if it turns red - oh…” His face fell, because the Remembrall had suddenly glowed scarlet, “…you’ve forgotten something…”