As he called the beast off, a motor-horn sounded, and they saw a car coming from the direction of the house.

“That’s our doctor, I expect,” Sir Clinton surmised; and Stenness confirmed the guess.

In a few minutes they had all made their way to Helen’s Bower, under Stenness’s guidance. Once there, the doctor proposed to begin his examination of the bodies; but the Chief Constable intervened.

“Just a moment, doctor. Before you shift anything, I want to take one or two photographs. Nothing like a permanent record for future reference.”

He took a case which one of the constables had carried and produced from it one of the largest-sized Kodaks. Then, by the marks of the feet in the grass, he replaced the overturned chair in its proper position; and finally he marked the position of the loophole in the hedge by means of a scrap of paper.

“I want something to give the scale,” he explained, at the last moment. “Would you mind sitting in the chair, Mr. Stenness? And perhaps you’d stand by the loophole, Mr. Torrance?”

He looked round the enclosure for an instant.

“And here, Costock, you get over into that corner. It’ll give some notion of the distance.”

When they had placed themselves, he took several photographs from various positions.

“Now, doctor, you can get to work if you like.”