But the cat, too, had heard that dreadful bark; and it, too, had understood. This was more than it had bargained for. Across the dim shadows of that haunted room there must have passed some secret signal of distress between the animals. Smoke stood up and looked swiftly about him. He uttered a piteous meow and trotted smartly away into the greater darkness by the windows. What his object was only those endowed with the spirit-like intelligence of cats might know. But, at any rate, he had at last ranged himself on the side of his friend. And the little beast meant business.

At the same moment the collie managed to gain the door. The doctor saw him rush through into the hall like a flash of yellow light. He shot across the oilcloth, and tore up the stairs, but in another second he appeared again, flying down the steps and landing at the bottom in a tumbling heap, whining, cringing, terrified. The doctor saw him slink back into the room again and crawl round by the wall towards the cat. Was, then, even the staircase occupied? Did They stand also in the hall? Was the whole house crowded from floor to ceiling?