"No. Mrs. Rath, as she calls herself, came to Heredith many years ago, took a small cottage, and tried to support her daughter and herself by giving lessons in music and French. She would have starved if it had not been for Miss Heredith, who helped her and her little girl, tried to get the mother some pupils, and finally took her into the moat-house as housekeeper. Mrs. Rath disappeared from the place after her daughter's arrest, when the police had decided that it was not necessary to detain her, leaving a note behind her for Miss Heredith to say that she couldn't face her after all that had happened." Colwyn did not speak immediately. He was examining the row of upper windows which looked down on the garden in which they were standing. "Is that the window of the room in which Mrs. Heredith was murdered?" he asked, pointing to the first one. "Yes. It is high for a first-floor window, but there is a fall in the ground on this side of the house." Colwyn tested the strength of the Virginia creeper which grew up the wall almost to the window, and then bent down to examine the grass and earth underneath. "Caldew thought at first that the murderer escaped from the window, but Merrington did not agree with him," said Musard. If the remark was intended to extract an expression of opinion from Colwyn it failed in effect, for he remained silent. He had regained his feet, and was looking up at the window again. "Where is the door which opens on the back staircase of this wing?" he said, at length. "At the extreme end. You cannot see it from here. It opens on the back of the house." "According to the newspaper reports of the case, the door is always kept locked. Is that correct?" "As a general rule it is. But it was found unlocked before dinner on the night the murder was committed." "I was not informed of this before." "Phil was not aware of it, and Detective Caldew attached so little importance to it when I told him after the murder that I should not have thought it worth mentioning if you had not asked me. Caldew's point of view was that the door had been left unlocked, accidentally, by one of the servants, which is quite possible. I understand both detectives agree that it had nothing to do with the murder, because the door was locked by the butler, who discovered it unlocked, fully an hour before the murder was committed. If Hazel Rath had attempted to escape that way she would have been caught in a _cul-de-sac_, for we rushed upstairs from the dining-room immediately we heard the scream." "Did you search the back staircase?" "Almost immediately. It was empty." "And there is no doubt that the door at the bottom was locked?" "None whatever--one of the young men tried it." "What time did the butler make his discovery?" "Shortly before dinner. I do not know the exact time." "Thank you. Now, if you will excuse me, I should like to see the room Mrs. Heredith occupied. Is it empty?"