So thought Mr Kay.
"So you heard the noise?" he said. "Well, perhaps you had better come with me. There is no doubt that a burglar has entered the house tonight, in spite of the fact that I locked all the windows myself. Your study window was unlocked, Fenn. It was extremely careless of you to leave it in such a condition, and I hope you will be more careful in future. Why, somebody might have got in through it."
Fenn thought it was not at all unlikely.
"Come along, then. I am sure the man is still in the house. He was hiding in the cupboard by the dining-room. I know it. I am sure he is still in the house."
But, in spite of the fact that Fenn was equally sure, half an hour's search failed to discover any lurking evil-doer.
"You had better go to bed, Fenn," said Mr Kay, disgustedly, at the end of that period. "He must have got back in some extraordinary manner."
"Yes, sir," agreed Fenn.
He himself had certainly got back in a very extraordinary manner.
However, he had got back, which was the main point.