‘Not many people are aware that the Potters knew You-Know-Who was after them. Dumbledore, who was of course working tirelessly against You-Know-Who, had a number of useful spies. One of them tipped him off, and he alerted James and Lily at once. He advised them to go into hiding. Well, of course, You-Know-Who wasn’t an easy person to hide from. Dumbledore told them that their best chance was the Fidelius Charm.’
