I stood staggered by the suggestion.
I was near the furnace—nearer than the others.
Then, when I found speech again, I said:
“If there are intruders in this place, they could not have escaped; they must certainly be upstairs. I agree with Mr Langton that it is certainly very curious that these doors should have been forced.”
“How did you know that the Professor is in Scotland?” he inquired of me eagerly.
In an instant I had a ready reply.
“Antonio told me so when I called on Monday.”
“Did he say when his master would be back?” asked the inspector.
“He said he expected him to return last night, as he had an engagement to go with his daughter to a ball.”
“Then he may have returned and gone to the dance,” remarked the officer. “He may also have lost his keys and been compelled to break open the doors—quite a likely circumstance. Three persons dined downstairs to-night. He and his daughter and a friend probably dined and afterwards went out; while the servants, knowing they would not return before midnight, may have followed them out to spend the evening. That at least is my theory at the present.”