I am sitting in the old coastguard tower on the cliffs rising above Northumbria’s holy island of Lindisfarne. From here you can see the whole island and its vast setting of sea and sky. Last night, gales yelled over the huddle of red-roofed houses and weathered priory stones; today the wind has dropped, and the North Sea wears an almost tranquil smile. The boats barely bob in the tear-shaped little harbour. Only the waves breaking on the far headland show a snarl of white.