" He drove me to the Tower of London, more huge and terrifying than I'd imagined, like a sprawling medieval Alcatraz. We got there just at ten, so I could watch the guards lock the Tower gates. For all their flashy black-and-scarlet unforms, they are grim and frightening as they lock the gates to that dread prison with darkness closing in. You think of the young Elizabeth sitting somewhere beind the stone walls, wanting to write and ask Bloody Mary to have her beheaded with a sword instead of an axe.

' When the gates were locked the guatds marched back toward the huge iron Tower door. It rose to let them pass through, lowered and clanged shut behind them, and the light voice behind me said: "They haven't missed a night in seven hundred years".

' The mind boggles. Even going back only three hundred years, you think of London during the Great Fire, the Great Plague, the Cromwell Revolution, the Naploleonic Wars, the First World War, the Second World War

' "They locked the tower with this ceremony," I asked him "Every night, even during the Blitz?"

' "Oh yes," he said.

' Put that on Hitler's tombstone tell that to that great American patriot Wernher von Braun whose buzz bombs destryoed every fourth house in London.

' He drove me home and I tried to thank him..."

Helene Hanff "84 Charing Cross Road"