Of course it was natural that Cayley should want to get rid of his guests as soon as the tragedy was discovered. He would want this for their own sake as well as for his. But he had been a little too quick about suggesting it, and about seeing the suggestion carried out. They had been bustled off as soon as they could be packed. The suggestion that they were in his hands, to go or stay as he wished, could have been left safely to them. As it was, they had been given no alternative, and Miss Norris, who had proposed to catch an after-dinner train at the junction, in the obvious hope that she might have in this way a dramatic cross-examination at the hands of some keen-eyed detective, was encouraged tactfully, but quite firmly, to travel by the earlier train with the others. Antony had felt that Cayley, in the tragedy which had suddenly befallen the house, ought to have been equally indifferent to her presence or absence. But he was not; and Antony assumed from this that Cayley was very much alive to the necessity for her absence.

Why?