Caldew, on reaching this stage of his reasoning, shook his head doubtfully. He had to admit to himself that such a theory did not ring true. If Miss Heredith had been maddened by some insult at the afternoon's interview, she was far more likely to have killed Mrs. Heredith immediately than have waited until dinner-time. And, if she had committed the murder, why had she gone about it in the manner likeliest to lead to discovery, openly leaving her guests a few minutes before, and allowing herself to be seen afterwards descending the staircase? Even the veriest neophyte in crime usually displayed some of the caution of self-preservation.
But Caldew was too experienced in criminal investigation to reject a theory merely because it was contrary to experience. There existed presumptions for suspicion of Miss Heredith which at least warranted further inquiry. And, thinking over these presumptions, he arrived at the additional conclusion that the theory of her guilt could also be made to account for the puzzle of the open window in Mrs. Heredith's bedroom. Caldew believed that the open window had some bearing on the crime. His first impression had been that the murderer had entered and escaped by that means. The Virginia creeper to which Weyling had directed attention that morning had strengthened that belief, in spite of Merrington's opinion that the plant would not bear a man's weight. But now it seemed to him that Miss Heredith might have opened the window for the purpose of throwing the revolver into the moat so that it should not be found. He determined to investigate that possibility as soon as he returned to the moat-house.
He reached his destination only to learn that Mr. and Mrs. Weyne had motored over to the moat-house to pay their condolences to the family. He remounted his bicycle and rode back as fast as he could, chagrined to think that he had wasted the best part of an afternoon in a fruitless errand.
It was evening when he reached Heredith again, and rode through the woods towards the moat-house. It looked deserted in the gathering twilight. A fugitive gleam of departing sunshine fell on the bronze and blood-red chrysanthemums in the circular beds, but the shadows were lengthening across the lawn, and the mist from the green waters of the moat was creeping up the stained red walls.
His ring at the front door was answered by the pretty parlourmaid who had been dusting the hall before breakfast. He recognized in Milly Saker a village playmate of nearly twenty years ago, and he recalled that it was she who had told his sister of the difference which had existed between Miss Heredith and her nephew's wife.
Milly greeted the detective with a coquettish smile of recognition.
"How are you?" she said. "You wouldn't look at me this morning. You seemed as if you didn't want to recognize old friends."
Caldew's mind was too preoccupied to meet these rural pleasantries in the same spirit.
"Is Miss Heredith in?" he asked, stepping into the hall.
"I shouldn't be here talking to you if she was," replied the girl pertly. "She's gone to the village in the motorcar to meet Mr. Musard. She's just got a telegram to say he's coming back."