necessary for the proper understanding of what subsequently took place.
With Smoke sleeping in the folds of his fur coat, and the collie lying watchful on the seat opposite, John Silence went down in his motor after dinner on the night of November 15th.
And the fog was so dense that they were obliged to travel at quarter speed the entire way.
It was after ten o'clock when he dismissed the motor and entered the dingy little house with the latchkey provided by Pender. He found the hall gas turned low, and a fire in the study. Books and food had also been placed ready by the servant according to instructions. Coils of fog rushed in after him through the opened door and filled the hall and passage with its cold discomfort.
The first thing Dr. Silence did was to lock up Smoke in the study with a saucer of milk before the fire, and then make a search of the house with Flame. The dog ran cheerfully behind him all the way while he tried the doors of the other rooms to make sure they were locked. He nosed about into corners and made little excursions on his own account. His manner was expectant. He knew there must be something unusual about the proceeding, because it was contrary to the habits of his whole life not to be asleep at this hour on the mat in front of the fire. He kept looking up into his master's face, as door after door was tried, with an expression of intelligent sympathy, but at the same time a certain air of disapproval. Yet everything his master did was good in his eyes, and he betrayed as little impatience as pos-
