It was a fervid July night. The scene London, and the hour near twelve o'clock. The roar of the vehicular traffic was dying down, for the theatres had emptied some time before, but the restaurants and public-houses were still doing a roaring trade, while the streets were full of bustle and life, for the stagnant and heated atmosphere induced people to linger and chat and smoke in the open air rather than hurry to their homes.