"You take the matter very seriously, I believe," said Guildea, also speaking more gravely.
"How else can I take it? You wouldn't have me laugh at it when you tell it me seriously?"
"No. If we find my visitor still in the house, I may even call upon you to exorcise it. But first I must do one thing."
"And that is?"
"Prove to you, as well as to myself, that it is still there."
"That might be difficult," said the Father, considerably surprised by Guildea's matter-of-fact tone.
"I don't know. If it has remained in my house I think I can find a means. And I shall not be at all surprised if it is still there—despite the Westgate air."
In saying the last words the Professor relapsed into his former tone of dry chaff. The Father could not quite make up his mind whether Guildea was feeling unusually grave or unusually gay. As the two men drew near to Hyde Park Place their conversation died away and they walked forward silently in the gathering darkness.
"Here we are!" said Guildea at last.
He thrust his key into the door, opened it and let Father Murchison into the passage, following him closely and banging the door.