see if we can establish a connection. It may be that the secret is there."
They found the passage that led from the mansion to the house in which so much had happened to them that stormy night. There was a room in the main house, whence the passage began, and this room, too, showed signs of having been used recently.
And when they came to the place where the girls had dined so unexpectedly they saw unmistakable signs that other meals than the one they had helped themselves to had been eaten there.
"Our friend, the ghost, has been here since," said Mr. Blackford. "Perhaps we shall have to set a trap for him."
They walked on, their footsteps echoing and re-echoing through the silent old house. They were in the annex now, but a search there revealed nothing.
The girls looked at one another, and then at Mr. Blackford. He shook his head.
"I confess I am baffled," he said. "I did hope to find something. But we haven't come across it. If there was a systematic effort to give the impression that this mansion was haunted, there would have been some evidences of it.
"I mean we would have some material evi-
