Captain Stanhill did not reply. He wandered round the spacious library, glancing at the rows of books in their oaken shelves. Superintendent Merrington, while awaiting the arrival of Miss Heredith, drew forth the plan of the moat-house which Caldew had sketched, and studied it closely.

The moat-house had only two stories, but it was a rambling old place and covered a considerable area of ground, facing three sides of the county. The principal portion, consisting of the old house which had been burnt down and rebuilt, faced the north. The two wings had been added later.

The front door opened into a spacious entrance hall which in former times had been the dining-room. At the end of the hall was the grand staircase, adorned by statues, armour, and the Heredith arms carved in panels. The principal rooms, with the exception of the dining-room, were all on the ground floor of the main building, but corridors led off the entrance hall to the newer wings at each side, extending on the right side to the billiard room, conservatory, greenhouses, and orangery, and on the left side to the dining-room, Miss Heredith's private sitting-room, and Sir Philip's study.

Merrington carefully studied the arrangements of this wing, as depicted on Caldew's sketch plan. The upper portion was reached by a staircase which opened off the corridor almost opposite the dining-room door, and ran, with one turning, to a landing which was only a few feet away from the door of the bedroom in which Mrs. Heredith was murdered. Next to this room was a dressing-room, and a spare bedroom. The remainder of the wing consisted of two bathrooms, a linen room, and Miss Heredith's bedroom, which was at the south end of the wing. The rooms all faced the west side of the house, and were lit by windows opening on the terraced gardens. They were entered by a corridor which ran the whole length of the wing, terminating in the door which opened on the unused back staircase.

Before Merrington had finished his scrutiny of the plan, the door opened, and Miss Heredith entered the library. She looked pale and worn, and there were dark rings under her eyes which suggested a sleepless night. But her face was composed, though grave.

Captain Stanhill advanced and shook hands with her, uttering a few words of well-bred sympathy as he did so, and then introduced Superintendent Merrington.

"Superintendent Merrington has been kind enough to come down from Scotland Yard at my request to give us the benefit of his skill in investigating this terrible crime," he said simply.

"I desired an interview with you in order to ask a few questions," said Merrington, coming to the point at once.

Miss Heredith bowed.

"Were all the blinds down in the dining-room last night during dinner?" asked Merrington.