"Caldew thinks that the murderer entered the house by scaling the bedroom window, and made his exit by the same means. He bases that view on Miss Heredith's belief that the window was closed when she was in the bedroom before dinner. After the murder was committed the window was found open. But Miss Heredith's statement about the closed window does not amount to very much. She does not actually know whether the window was open or shut, because the window curtains were completely drawn at the time she was in the room. Those curtains are so thick and heavy that they would keep out the air whether the window was open or shut, and account for the stuffy atmosphere in a room which had been occupied all day. "I do not regard the open window as a clue one way or the other. The one thing we must not lose sight of is that nobody can say definitely when it was opened. It may have been opened by Mrs. Heredith herself before Miss Heredith came into the room, or the murderer may have flung it open and escaped from the room that way after committing the murder. Personally, I do not think that he did, but I am not prepared altogether to exclude the possibility of his having done so. But I am convinced that he did not enter the bedroom by scaling the outside wall and getting in through the window. In the first place, there are no marks of any kind on the window sill or the window catch. There is not very much one way or another in the absence of marks on the sill or even on the catch, supposing the window was locked. The murderer might have opened the catch from outside without leaving a mark--I have known the trick to be done--and he might have got into the room without leaving any marks on the sill, particularly if he wore rubber boots. But, what is far more important, there are no marks on the wall outside, or any disturbance or displacement of the Virginia creeper which covers a portion of the wall, to suggest that the murderer climbed up to the room that way. I think it is certain that if he had done so he would have left his marks on the one or the other. The wall is of a soft old brickwork which would scratch and show marks plainly, and the Virginia creeper would break away. In any case, as I said this morning, it would barely sustain the weight of a boy, or a very slight girl. Finally, there are no marks of footsteps approaching the wall in the garden outside.