Harris, the silk merchant, was in South Germany on his way home from a business trip when the idea came to him suddenly that he would take the mountain railway from Strassbourg and run down to revisit his old school after an interval of something more than thirty years. And it was to this chance impulse of the junior partner in Harris Brothers of St. Paul's Churchyard that John Silence owed one of the most curious cases of his whole experience, for at that very moment he happened to be tramping these same mountains with a holiday knapsack, and from different points of the compass the two men were actually converging towards the same inn.